INTRODUCTION
Urticeae (= Urerareae Wedd.) is a moderately sized tribe of the nettle family (Urticaceae) with eleven genera and ap-proximately 220 species. Its members are often found in humid habitats in forests or at forest margins and occur in both the Old and New Worlds (Friis, 1993; Hadiah & al., 2008; Cohn & Hadiah, 2009). The tribe is characterized by stinging hairs and pistillate flowers with four tepals, of which frequently one pair is larger than the other, and without staminodes (Friis, 1989, 1993). Because of the obvious morphological synapo-morphies of Urticeae, it is not difficult to recognize a plant as being a member of this tribe. Moreover, phylogenetic analysis of Urticaceae using plastid DNA sequence data has shown that Urticeae (including Poikilospermum Zipp.) form a well-supported clade (Hadiah & al., 2008).
The Shennongjia National Nature Reserve (SNNR) is lo-cated in the Northwest of Hubei province, central China. Its unique geographical location and complex topology make it one of the most biodiverse areas in China (Ying, 2001; Xie, 2003). The Shennongjia Mountains are characterized by high mountains and deep valleys, a dense network of streams, and lush vegetation. The region is an important hot-spot for south-central Chinese biodiversity and contains many endemic plants (Myers & al., 2000). During our recent in-depth floristic ex-plorations of the SNNR, an unusual taxon caught our attention. The plant was easily identified as belonging to Urticeae based on the presence of stinging hairs, stipules, and pistillate flow-ers with four tepals and without staminodes. In its paniculate inflorescences with many long branches and its four-lobed perianth with larger dorsal than ventral lobes in its female flowers, it superficially resembles Urtica L., a genus of about 30 species with a wide distribution in the northern temperate region (Chen & al., 2003). However, based on its alternate leaf arrangement, the presence of one to three woody bulbils in sterile axils, intrapetiolar stipules in the leaf axils, and oblique achenes with short stipes, we initially assigned the new taxon to Laportea Gaudich., a genus with 30 species confined to tropical and warm-temperate E Asia and eastern North America (Friis, 1993). Upon closer examination, however, it was clear that the set of morphological characters did not match Urtica, Laportea or any other genus of Urticeae (Table 1). The plant is described below as a new genus with only one species, Zhengyia shen-nongensis T. Deng, D.G. Zhang & H. Sun.
Bulbils are specialized propagules, allowing vegetative reproduction and dispersal, and many herbaceous plants can produce them (Wang & al., 2004; Walck & al., 2010). Pres-ence or absence of bulbils has been recognized as a significant
Zhengyia shennongensis: A new bulbiliferous genus and species of the nettle family (Urticaceae) from central China exhibiting parallel evolution of the bulbil trait
Tao Deng,1,2,5 Changkyun Kim,1,5 Dai-Gui Zhang,3 Jian-Wen Zhang,1 Zhi-Ming Li,4 Ze-Long Nie1 & Hang Sun1
1 Key Laboratory of Biodiversity and Biogeography, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, P.R. China
2 University of Chinese Academy of Sciences, Beijing 100039, P.R. China
3 Key Laboratory of Plant Resources Conservation and Utilization, Jishou University, College of Hunan Province, Jishou 416000, Hunan, P.R. China
4 Life Science School, Yunnan Normal University, Kunming 650031, Yunnan, P.R. China
5 These authors contributed equally to the work.
Author for correspondence: Hang Sun, hsun@https://www.doczj.com/doc/b710278235.html,
Abstract Zhengyia shennongensis is described here as a new genus and species of the nettle family (Urticaceae) from Hubei province, central China. The phylogenetic position of Z. shennongensis is determined using DNA sequences of nuclear ribo-somal ITS and three plastid regions (rbcL, psbA-trnH, trnL-F). Zhengyia shennongensis is readily distinguished from the related genera Urtica, Hesperocnide, and Laportea in the tribe Urticeae by its seed (oblong-globose or subglobose and not compressed achenes, surface densely covered with nipple-shaped protuberances) and stipule morphology (large leaf-like stipules with auriculate and amplexicaulous base and united with stem). Phylogenetic evidence indicates that Zhengyia is a distinct group related to Urtica (including Hesperocnide) species and Laportea cuspidata in tribe Urticeae. The bulbiliferous species of the tribe (L. bulbifera, L. cuspidata, Z. shennongensis) do not form a clade. This result indicates that the bulbil trait evolved in parallel within Urticeae. Our findings highlight the importance of shady and moist habitats in promoting species diversification and the parallel evolution of morphological traits that are likely to be adaptive.
Keywords bulbils;central China; new genus and species; parallel evolution; Urticaceae; Urticeae; Zhengyia shennongensis Received: 14 May 2012; revision received: 1 Oct. 2012; accepted: 12 Nov. 2012.
morphological trait in species delimitation in Urticeae (Chen & al., 2003). The character is also useful to establish infra-generic taxa in genera of Urticeae (e.g., Laportea ; Chen & al., 2003). To date, in Urticeae only two species of Laportea (L. bulbifera Weed., L. cuspidata Friis) have been reported to be bulbiliferous; they both grow in shady, moist conditions (Chen & al., 2003).
In the present study, we determine the phylogenetic position of the new taxon based on morphological data, espe -cially surface features of the achene examined using scanning electron microscopy (SEM), and cytological and molecular data (the three plastid regions rbcL , psbA-trnH intergenic spacer [IGS], and trnL-F IGS; and nuclear ribosomal ITS [nrITS]). Based on the inferred phylogeny, we also provide a discussion of the evolution of the bulbil trait in Urticeae.
MATERIALS AND METHODS
Plant material. — Samples of Z. shennongensis were col -
lected for morphological comparison from the only known population—Wushanhu, Hubei Province—during our field in -vestigations in 2011 (Fig. 1). Leaves and mature seeds were also collected for SEM and cytological and molecular phylogenetic studies. For comparison with the seed morphology of Z. shennon-gensis , eight species of the closely related U. mairei H. Lév, U. di-oica L., U. fissa E. Pritz., U. urens L., L. bulbifera Wedd., L. cus-pidata Friis, L. canadensis Gaudich., and Girardinia diversifolia (Link) Friis were examined.
In order to determine phylogenetic relationships in Urticeae using molecular markers, we sampled 16 taxa (21 accessions)
in addition to Z. shennongensis , including two species of Den-drocnide Miq. (two accessions), three subspecies of Girardinia diversifolia (three accessions), one species of Hesperocnide Torr. (one accession), three species of Laportea (five acces -sions), one species of Poikilospermum (one accession), and six species of Urtica (nine accessions). We also included three species, Pilea plataniflora C.H. Wright of Elatostemateae Gaudich., Boehmeria spicata Thunb. of Boehmerieae Gaudich., and Fatoua villosa Nakai of Moraceae as outgroups, based on a previous phylogenetic analysis using rbcL and trnL DNA sequence data (Hadiah & al., 2008). Voucher information and GenBank accession numbers for all specimens used in this study are listed in Appendix 1.
Seed observation. — The mature seeds of 90 individuals of the species listed above and our new taxon were mounted on aluminum stubs with double-sided adhesive tape, sputter-coated with gold to a maximum thickness of 20 μm, and ex -amined using a KYKY-1000B scanning electron microscope (SEM; Science Instrument Company, Beijing, China) with a voltage of 30 kV. Microphotographs focused primarily on the center of the seeds. Seed morphology was also examined under the dissecting microscope (OLYMPUS BX53).
Cytological studies. — Root-tip meristems were obtained by germinating seeds on wet filter paper in Petri dishes at ap -proximately 20°C. Root tips less than 1.5 cm long were cut and treated with 0.002 M 8-hydroxyquinoline at room temperature for 3–5 h before being fixed in Carnoy (glacial acetic acid: absolute ethanol = 1?: 3), macerated in a 1?:?1 mixture of 45% acetic acid and 1 M HCl for 2.5 min, and stained and squashed in Carbol Fuchsine. Karyotypes of mitotic chromosomes at metaphase were determined from at least five well-spread
Fig. 1. Distribution of Zhengyia shennongensis T. Deng, D.G. Zhang & H. Sun. The circle indi -cates the type locality of Z. shen-nongensis
.
metaphases of three different roots. The designation of the centromere position as median (m), submedian (sm) and sub-terminal (st) followed Levan & al. (1964).
DNA extraction, PCR amplification, and sequencing. —Total genomic DNA was isolated from silica gel-dried leaf material using the Universal Genomic DNA Extraction Kit (Takara, Dalian, China). Primer sets and protocols for PCR followed specifications in previous publications: rbcL (prim-ers Z1 and 1204R; Zurawski & al., 1981; from G. Zurawski [DNAX Research Institute, Palo Alto, California, U.S.A.]), psbA-trnH IGS (psbA_F and trnH_R; Hamilton, 1999), trnL-F IGS (e and f; Taberlet & al., 1991), and nrITS (ITS1 and ITS4; White & al., 1990; Kim & al., 2010). Amplified DNA samples
were analyzed by electrophoresis on 1.4% agarose gel, run in a 0.5× TBE buffer and detected by ethidium bromide staining. The PCR products were then purified using a QiaQuick gel extraction kit (Qiagen, Inc., Valencia, California, USA) and directly sequenced in both directions using the amplification primers on an ABI 3730 automated sequencer (Applied Bio-systems, Forster City, California, U.S.A.).
Phylogenetic analyses. — DNA Baser v.3 (http://www https://www.doczj.com/doc/b710278235.html,) was used to evaluate the chromatograms for base confirmation and to edit contiguous sequences. Multiple-sequence alignment was performed with MAFFT v.6 (Katoh & al., 2009; available at http://www.genome.jp/tools/mafft) using the default alignment parameters. Gaps were coded as missing data. All datasets have been submitted to TreeBASE (https://www.doczj.com/doc/b710278235.html,/; study accession number, S12631).
The phylogenetic reconstruction of the sequences was performed by maximum parsimony (MP) in PAUP* v.4.0b10 (Swofford, 2002). All characters were weighted equally and unordered. Each dataset was analyzed separately and then a simultaneous analysis was performed including all four re-gions. Before combining the datasets, the incongruence length difference (ILD) test was conducted to assess data congruency (Farris & al., 1995) using PAUP* and 10,000 heuristic search replications including only parsimony-informative characters. Most parsimonious trees were searched with a heuristic al-gorithm using tree bisection-reconnection branch swapping, MULPARS, and the alternative character state. Strict con-sensus trees were constructed from the most parsimonious trees. Bootstrap analyses (BP; 1000 pseudoreplicates) were conducted to examine the relative level of support for individual clades (Felsenstein, 1985). The consistency index (CI; Kluge & Farris, 1969) and retention index (RI; Farris, 1989) were calculated to measure the amount of homoplasy in the dataset.
Phylogenetic analyses of the nrITS and combined data s ets were also conducted using Bayesian Markov chain Monte Carlo (MCMC) inference (BI; Yang & Rannala, 1997) using MrBayes v.3.12 (Ronquist & Huelsenbeck, 2003). Modeltest v.3.1 (Posada & Crandall 1998) was used to determine the optimal model of DNA evolution for the data based on the Akaike informa-tion criterion (AIC; Akaike, 1974). Four chains of the MCMC inference were run simultaneously, with sampling every 100 generations over a total of one million generations. The first 2500 trees (25%) of the sample trees from each run were dis-
carded as determined by Tracer v.1.5 (Rambaut & Drummond, 2007). A Bayesian consensus tree was constructed from the remaining trees, yielding the posterior probability (PP) values for each clade.
The single most parsimonious topology obtained from the analysis of the combined molecular data (nrITS and three plas-tid DNA regions) was employed to reconstruct the evolution of the bulbil character. Character reconstruction was carried out under the assumption of unordered and unweighted character states with the Ancestral State Reconstruction Package in Mes-quite v.2.75 (Maddison & Maddison, 2011) using unambiguous optimization.
RESULTS
Morphological characters. — Morphological characters of Z. shennongensis and related genera, including Dendro-cnide, Girardinia, Hesperocnide, Laportea, Poikilospermum, and Urtica, are listed in Table 1. The seed characteristics of our new taxon, including shape and surface sculpturing, were found to be unique when compared to the other genera. The achene shape of Z. shennongensis was oblong-globose or subglobose and extremely asymmetrical, and no infraspecific variation was found (Fig. 2A). The seed surface of Z. shennongensis is densely covered with nipple-shaped protuberances but smooth and/or verrucose in the other genera (Fig. 2).
Chromosome counts and karyomorphology. — The chro-mosome number in mitotic metaphase cells was found to be 2n = 24, and the karyotype formula is 2n = 6m?+?16sm?+?2st (Fig. 3).
Phylogenetic analyses. — The characteristics and sta-tistics for nrITS, the three plastid regions, and the combined data s ets for the MP analyses are presented in Table 2. Bayesian analyses of all datasets resulted in the same tree topologies as the corresponding MP analyses (data not shown). All MP trees were generally congruent with respect to well-supported clades, but there was an incongruence between the plastid and nrITS analyses concerning the position of Z. shennongensis. The combined plastid analysis resolved both Z. shennongensis samples as well-supported sister to Urtica and Hesperocnide species (BP = 92%, PP = 1.00), whereas in the nrITS tree the species was sister to a clade including Urtica, Hesperocnide, and Laportea species but with low statistical support (BP = 50%, PP = 0.64; data not shown).
ILD tests failed to identify significant conflict among the three partitions of the plastid dataset (rbcL, psbA-trnH, trnL-F; P = 0.065) and between the nrITS and the plastid datasets (P = 0.052). When all molecular datasets were combined, the single MP tree found was better resolved than any tree from sepa-rate analyses. Phylogenetic analysis of the combined dataset resulted in a single most parsimonious tree (tree length = 2302, CI = 0.597, RI = 0.756). In the MP tree, tribe Urticeae formed a monophyletic group (BP = 100%, PP = 1.00; Fig. 4). The two individuals of Z. shennongensis were sister to Urtica (includ-ing Hesperocnide) species, with high statistical support (BP = 92%, PP = 1.00). Laportea cuspidata was sister to the clade comprising Zhengyia and Urtica?+?H esperocnide species (BP =
86%, PP = 1.00). The bulbiliferous species (L. bulbifera , L. cus-pidata , and Z. shennongensis ) were not closely related to each other (Fig. 4).
DISCUSSION
Systematic position of Zhengyia shennongensis . — Ac -
cording to the classification of Urticaceae by Friis (1989, 1993), our new taxon Z. shennongensis is a member of tribe Urticeae. In tribe Urticeae, the basic chromosome number most often
is x = 12 and 13, and less often x = 10, 11, and 19 (e.g. Wood -land & al., 1976, 1982; Friis, 1993). The chromosome number of Z. shennongensis was found to be 2n = 24 (x = 12) in this study (Fig. 3). Thus, cytological evidence supports that our new species should be included in Urticeae. Moreover, our molecular phylogenetic results clearly confirmed that Z. shen-nongensis is part of Urticeae (Fig. 4).
In general, genera of Urticeae have been recognized primarily on the basis of stipule and fruit shape (Friis, 1993; Chen & al., 2003). Zhengyia shennongensis has a distinctive oblong-globose or subglobose achene with dense nipple-shaped
Table 1. Morphological comparison of Zhengyia with other genera in Urticeae.
Character Zhengyia Dendrocnide Girardinia Hespero c nide Laportea I d Laportea II e Poikilo-spermum Urtica Habit a,b
robust herb
shrub
robust herb
herb
herb
herb
shrub or woody climber herb
Bulbils a,b present absent absent absent present
absent or present in L. bulbifera absent
absent
Leaf arrangement a,b alternate alternate alternate opposite alternate alternate alternate opposite
Stipules a,b
intrapetiolar, auriculate- amplexicau -lous base united with the stem, persistent intrapeti -olar, subulate or linear, deciduous
intrapeti -olar, subulate or linear,
deciduous lateral, subu -late or linear,
persistent intrapeti -olar, subulate or linear, deciduous
intrapeti -olar, subulate or linear, deciduous
intrapeti -olar, subulate or linear,
deciduous
lateral, subu -late or linear,
persistent Perianth a
deeply
4-lobed, one pair larger 4-lobed,
lateral ones
slightly larger ovoid-tubular, (2–) 3-toothed almost tubu -lar, minutely 2-toothed at the apex 4-lobed,
strongly un -equal, lateral larger 4-lobed, one minute or absent clavate-tubular
deeply
4-lobed, one pair larger Inflorescences pairs solitary solitary or pairs
pairs
solitary solitary solitary pairs Stigmas a,b
short clavate
linear or ligulate subulate, acute, minute capitate-penicillate linear, papil -lose on one side linear, papil -lose on one side capitate or ligulate capitate-penicillate Achene symmetry a,b asymmetric asymmetric asymmetric symmetric asymmetric
asymmetric
asymmetric
symmetric
Achene shape a
oblong-globose or subglobose, not com -pressed
elliposidal to ovoid, compressed
broadly ovoid, compressed
ovate, compressed
ovoid to
semicircular, compressed
ovoid to semicircular, compressed oblong, ellip -soid or ovoid, compressed ovoid, compressed
Achene surface a,c
with dense
nipple-shaped protuberances
verrucose verrucose unknown smooth
smooth or with stripes
verrucose
smooth or verrucose with sunken dots
a Friis (1993) and Chen & al. (2003). d Laportea I includes L. cuspidata .
b Based on herbarium collections and field observation. e Laportea II comprises two species (L. bulbifera , L. interrupta ).
c
Based on SEM.
protuberances on the surface (Fig. 2A). The species also differs from other genera of Urticeae by having large leaf-like stipules with an auriculate-amplexicaulous base united with the stem (Figs. 4, 5E). These differences are reflected in the MP tree using the combined dataset where the new genus occupies a distinct position in Urticeae with maximum support (BP = 100%, PP = 1.00; Fig. 4). Therefore, the recognition of Zhengyia at the rank of genus is warranted based on morphological and molecular evidence.
Our phylogenetic analyses showed that H.tenella Torr. was nested in the Urtica clade. This close relationship is morphologically supported by opposite leaves, lateral stipules, and straight achenes (Table 1). Zhengyia shennongensis is clos-est relative of the Urtica?+?H esperocnide clade with high sup-port (BP = 92%, PP = 1.00; Fig. 4). Several morphological characters (e.g., herbs with persistent stipules, deeply 4-lobed perianth, inflorescences with many long branches) support these relationships. Within this clade, Z.shennongensis can be easily distinguished from Urtica and Hesperocnide species by its alternate leaf arrangement (vs. opposite), large stipules inserted in the axil of leaves (vs. 2 or 4 rather small and nar-row, lateral stipules), and extremely oblique achenes (vs. erect; Table 1; Fig. 4).
Our molecular data do not support the monophyly of Laportea. Laportea cuspidata (Laportea I) is a sister to the Zhengyia?+?U rtica (including Hesperocnide) lineage but not to the other species of Laportea (Laportea II; Fig. 4). Zhengyia shennongensis with one to three woody bulbils in sterile leaf axils (Fig. 5F) resembles L. cuspidata, and these two species share other morphological characters such as alternate leaves and oblique achenes. However, the stigma of Z. shennongen-sis is short and clavate, while that of L. cuspidata is linear (Table 1). In addition, the achene surface of Z. shennongensis differs from that of L. cuspidata in having markedly nipple-shaped protuberances (Fig. 2A, G).
Of the other genera in tribe Urticeae, Z. shennongensis is similar to Girardinia in that both are robust herbs with long stinging hairs (>?5 mm). However, Z. shennongensis is distin-guished from Girardinia by three morphological characters: the presence of bulbils in leaf axils, branched inflorescences, and the ornamentation of the achene surface (Table 1; Fig. 4). Zhengyia shennongensis can be easily distinguished from Dendrocnide and Poikilospermum by habit (herbs vs. shrub or trees). Moreover, our molecular evidence shows that Z. shen-nongensis is not closely related to Girardinia, Dendrocnide, and Poikilospermum (Fig. 4).
Parallel evolution of bulbils. — Many herbaceous plants form bulbils (Okagami, 1979). Bulbils serve as a means of
clonal reproduction with the ability to colonize and seques-ter resources quickly after initial introduction, particularly in isolated populations (Callaghan & al., 1997; Abrahamson, 1980). Although bulbils are a valuable reproductive property, they are found in only three species (L. bulbifera, L. cus-pidata, Z.shennongensis) of Urticeae. In the combined MP tree, the three bulbiliferous species did not group together but were placed in three different clades, each with maximal support except L. bulbifera (BP = 57%, PP = 0.79; Fig. 4). Two Fig. https://www.doczj.com/doc/b710278235.html,parison of achene morphology and surface sculpting in tribe Urticeae. A,Zhengyia shennongensis (Deng, Zhang & Sun 3431; KUN); B,Urtica mairei (Peng 1607; KUN); C,U. dioica (Cai 55102; KUN); D,U. fissa (Liu 16628; KUN); E,U. urens (Qingzhang Exped. 318; KUN); F,Laportea bulbifera (Zhangdian Exped. 2575; KUN); G,L. cuspidata (Qingzhang Exped. 13367; KUN); H,L. canadensis (Koyama 7401; KUN); I,Girardinia diversifolia (Nie & Deng 4248; KUN). a, Dissecting microscope; b,SEM, low magnification; c, SEM,
ultrastructure of seed surface.
reconstructions of bulbil evolution are equally parsimonious in our phylogenetic tree (Fig. 4). Either bulbils evolved three times independently in Urticeae or they evolved twice and were lost once.
Bulbils have been recorded in many families and also in different clades of single tribes (Givnish & al., 2000; Wang & al., 2004; Thomas & al., 2005; Kitahara & al., 2010) and may have originated in response to strong selection in shady, moist and pollinator-poor habitats (Wake & al., 2011), and indeed the three bulbiliferous species of Urticeae grow mainly in shady habitats along creeks, particularly on wet, dripping cliffs in valleys. This trait probably replaces propagation and dispersal by seeds or fruits. When compared with species without bul -bils (e.g., Urtica , Girardinia ), the bulbiliferous taxa appear to have less seed set as judged from our field observations and herbarium material, but statistical confirmation of this obser -vation would require more detailed measurement. It might be that the wind-pollinated bulbiliferous taxa of Urticeae have
evolved these propagules to cope with lack of seed set in the
windless conditions of their extremely shady, humid habitats. Alternatively, the bulbils, which may be dispersed by gravity, water, animals, or birds (Thomas & al., 2005; Mizuki & Taka -hashi, 2009), may be better suited for shady habitats than seeds because they are much larger than normal seeds of Urticaceae and may store more nutrients needed for establishment.
TAXONOMIC TREATMENT
Zhengyia shennongensis T. Deng, D.G. Zhang & H. Sun, gen.
& sp. nov. – Holotype: China, central China, Hubei prov -ince, Shennongjia Forest District (SNNR), Yangri town, Wushanhu, 31°32′37″ N, 110°50′35″ E, 450 m alt, 4 Sep 2011, T. Deng, D.G. Zhang & H. Sun 2295 (KUN; isotypes: A, K, MO, PE). — Figures 5 and 6.
Description. – Perennial robust herbs with long stinging hairs. Rhizomes stoloniferous, up to 2 m long. Stems erect, 1–3 m tall, terete, not longitudinally angular or sulcate, slightly
Table 2. Tree statistics for the nrITS, rbcL , psbA-trnH , trnL-F , and combined datasets from maximum parsimony (MP) analysis.
Parameters nrITS rbcL psbA-trnH trnL-F Combined
ptDNA nrITS +?p tDNA Number of sequences (ingroup/outgroup)26 (23/3)
26 (23/3)26 (23/3)26 (23/3)26 (23/3)26 (23/3)Aligned length [bp]744101333742617762520Variable characters (%)
427 (57.4)160 (15.8)225 (66.8)178 (41.8)563 (31.7)990 (39.3)Parsimony informative characters (%)307 (41.3)87 (8.6)131 (38.9)113 (26.5)331 (18.6)638 (25.3)Number of trees (MP)186821MP tree length 116926053730311172302Consistency index (CI)a 0.5770.5910.6230.7270.6320.597Retention index (RI)0.7430.8090.7070.8780.7830.756Model selected (AIC)
GTR+I+G
GTR+I+G
GTR+G
GTR+G
GTR+I+G
GTR+I+G
a T he consistency index is calculated excluding uninformative characters.Fig. 3. Mitotic metaphase of Zhengyia shennongensis T. Deng, D.G. Zhang & H. Sun. A, Micrograph of metaphase chromosomes; B, karyotype
of mitotic metaphase chromosomes.
woody at base, ca. 2 cm in diam. Sterile leaf axils often with 13 woody bulbils, fawn, globose or ovoid, 3–6 mm in diam, often with adventitious roots. Upper stems and petioles densely covered with stinging hairs and white pubescent. Stipules greenish, leaf-like, herbaceous, persistent, solitary in leaf axils, united with stem at base; stipule cordate or triangular-ovate, 3–4 cm, margin subentire or minutely sparsely crenate, base auriculate-amplexicaulous, apex long caudate-acuminate, shallowly 2-cleft, basal veins 3. Leaves alternate; leaf blade broadly ovate, 13–27 × 10–26 cm, base shallowly cordate to
Fig. 4. Single most parsimonious tree (tree length = 2302, CI = 0.597, RI = 0.756) from the analysis of the combined nrITS and ptDNA sequences. Numbers above branches indicate bootstrap support (BP); numbers below branches are Bayesian posterior probabilities (PP); a dash (–) indicates that a node did not receive >80% BP in the MP analysis. A, achene shape; B, stipule position and shape (arrows indicate stipules); C, presence of bulbils (arrows indicate bulbils); D,
leaf arrangement.
Fig. 5. Images of living plants of Zhengyia shennongensis T. Deng, D.G. Zhang & H. Sun. A, Habitat; B, habit; C, population; D, inflorescence; E, stipules; F, bulbils; G, root; H, inflorescence; I, staminate flower; J, pedicel; K, fruit.
indicates stigma); C, staminate flower; D, achene. — Drawn by X.-S. Zhang.
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Hamilton, M.B. 1999. Four primer pairs for the amplification of chlo -roplast intergenic regions with intraspecific variation. Molec. Ecol. 8: 521–523.
IUCN 2001. IUCN Red List categories and criteria , version 3.1. IUCN
Species Survival Commission. Gland, Switzerland & Cambridge, U.K.: IUCN.
cordate, margin dentate or lobed; lobes deltoid, denticulate, slightly falcate; apex shortly acuminate; cystoliths minutely punctiform; lateral basal veins reaching middle lobes, sec -ondary veins 4–6 on each side, reaching teeth or anastomos -ing before margin, adaxial surface with sparse, stinging and setulose hairs, abaxial surface densely setulose and sparsely armed with stinging hairs on veins. Petiole 12–16 cm. In-florescences unisexual, in axillary pairs; paniculate with many long branches; male inflorescences in proximal axils, paniculate, erect, 15–25 cm; female inflorescence terminal or in subterminal leaf axils, pendulous, 20–30 cm, peduncle 2–4 cm. Staminate flowers ca. 1.5 mm, shortly pedicellate or subsessile; perianth lobes connate below middle, apex not cor -niculate; stamens 4, filaments incurved, longer than perianth, anthers peltate; pistillode terete, ca. 0.3 mm. Pistillate flow-ers ca. 1.3 mm, subsessile; perianth lobes 4, connate at base, strongly unequal, the 2 dorsal-ventral lobes larger, enclosing the ovary, elliptic-ovate, setulose, as long as achene; lateral lobes smaller, ovate-lanceolate, ca. 1/2 as long as dorsal lobe. Ovary ca. 1.1 mm, shortly stipitate, asymmetrically ovoid; stigma spirally winding, short clavate, ca. 0.4 mm. Achene yel -lowish green, oblong-globose or subglobose, ca. 1.2–1.5 mm, conspicuously oblique, with dense nipple-shaped protuber -ances on surface, enclosed by persistent enlarged dorsal-ven -tral perianth lobes; stipe ca. 0.1 mm.
Etym ology. — Zhengyia is named in honor of Prof. Zhengyi Wu, a renowned Chinese botanist who has studied Chinese plants for over 70 years. He deserves this homage in recognition of his important contributions to the field of plant taxonomy and floristics, to his deep involvement in training new researchers and his tremendous contribution to our knowl -edge of the flora of China.
Distribution and habitat. — Despite extensive investiga -tions in central China by the collectors of this taxon, the species has so far only been found in the area of Wushanhu Mountain in the SNNR, in the southwest part of Hubei province, central China (Fig. 1). The new species is probably calcicole. It prefers shady and wet habitats with deep humus-rich soil. It grows in small clusters in the valley and on limestone mountain slopes mainly at 500 to 600 m. These ancient limestone mountains in the region are deeply eroded and dissected by deep river val -leys. The globose woody bulbils are probably associated with a rain-splash dispersal mechanism: when bulbils are released from parent plants, they are washed down the mountain slope by rainwater and have the potential to spread more widely via streams.
Conservation status. — Endangered, based on the occur -rence in an area smaller than 5000 km2 and known at fewer than five localities (IUCN, 2001).
Phenology. — The peak flowering period was observed in September and fruiting specimens were found in October and November.
Paratype. — China. Hubei province, Shennongjia Forest District (SNNR), Yangri town, Wugu Mountain, 110°50′35″ E, 31°32′37″ N, 450 m alt, 4 Sep 2011, T. Deng, D.G. Zhang & H. Sun 2593
(KUN).
ACKNOWLEDGMENTS
This study was supported by grants-in-aid from the National Natural Science Foundation of China (Grant no. NSFC, 31061160184), Hundred Talents Program of the Chinese Academy of Sciences (2011312D11022), Strategic Priority Research Program of the Chinese Academy of Sciences (XDB03030106), NSFC-Yunnan Natural Science Foundation Unite Project (Grant no. U1136601), and the Research Pro -gram from the Ministry of Science and Technology of China (Grant no. 2007FY110100) to H. Sun and the research program for Postdoctoral Scholar, Key Laboratory of Biodiversity and Biogeography, Kunming Institute of Botany, CAS (Grant no. Y0205111L1) to C. Kim. The authors wish to thank X.K. Fan for SEM operation and for preparing the photos. We are also grateful to L.-E. Yang and G.-F. Chen for as -sistance with the chromosome counts, and to X.-S. Zhang for the line drawings. Finally, we would like to thank the anonymous reviewers for their valuable comments and suggestions.
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第三章栈和队列试题 一、单项选择题 1.栈的插入和删除操作在（）进行。 A. 栈顶 B. 栈底 C. 任意位置 D. 指定位置 2.当利用大小为n的数组顺序存储一个栈时，假定用top==n表示栈空，则向这个栈插入一个元素时， 首先应执行（）语句修改top指针。 A. top++; B. top--; C. top = 0; D. top; 3.若让元素1,2,3依次进栈，则出栈次序不可能出现（）种情况。 A. 3, 2, 1 B. 2, 1, 3 C. 3, 1, 2 D. 1, 3, 2 4.在一个顺序存储的循环队列中，队头指针指向队头元素的（）位置。 A. 前一个 B. 后一个 C. 当前 D. 后面 5.当利用大小为n的数组顺序存储一个队列时，该队列的最大长度为（）。 A. n-2 B. n-1 C. n D. n+1 6.从一个顺序存储的循环队列中删除一个元素时，需要（）。 A. 队头指针加一 B. 队头指针减一 C. 取出队头指针所指的元素 D. 取出队尾指针所指的元素 7.假定一个顺序存储的循环队列的队头和队尾指针分别为front和rear，则判断队空的条件为（）。 A. front+1 == rear B. rear+1 == front C. front == 0 D. front == rear 8.假定一个链式队列的队头和队尾指针分别为front和rear，则判断队空的条件为（）。 A. front == rear B. front != NULL C. rear != NULL D. front == NULL 9.设链式栈中结点的结构为（data, link），且top是指向栈顶的指针。若想在链式栈的栈顶插入一 个由指针s所指的结点，则应执行操作（）。 A. top->link = s; B.s->link = top->link; top->link = s; C. s->link = top; top = s; D. s->link = top; top = top->link; 10.设链式栈中结点的结构为（data, link），且top是指向栈顶的指针。若想摘除链式栈的栈顶结点， 并将被摘除结点的值保存到x中，则应执行操作（）。 A. x = top->data; top = top->link; B. top = top->link; x = top->data; C. x = top; top = top->link; D. x = top->data; 11.设循环队列的结构是 #define MaxSize 100 typedef int ElemType;
习题三栈和队列 一单项选择题 1. 在作进栈运算时,应先判别栈是否(① ),在作退栈运算时应先判别栈是否(② )。当栈中元素为n个,作进栈运算时发生上溢,则说明该栈的最大容量为(③ )。 ①, ②: A. 空 B. 满 C. 上溢 D. 下溢 ③: A. n-1 B. n C. n+1 D. n/2 2．若已知一个栈的进栈序列是1，2，3，…，n，其输出序列为p1，p2，p3，...，pn，若p1＝3，则p2为( )。 A 可能是2 B 一定是2 C 可能是1 D 一定是1 3. 有六个元素6，5，4，3，2，1 的顺序进栈，问下列哪一个不是合法的出栈序列？（） A. 5 4 3 6 1 2 B. 4 5 3 1 2 6 C. 3 4 6 5 2 1 D. 2 3 4 1 5 6 4.设有一顺序栈S，元素s1,s2,s3,s4,s5,s6依次进栈，如果6个元素出栈的顺序是s2,s3,s4, s6, s5,s1,则栈的容量至少应该是（） A.2 B. 3 C. 5 D.6 5. 若栈采用顺序存储方式存储，现两栈共享空间V[1..m]，top[i]代表第i个栈( i =1,2)栈顶，栈1的底在v[1]，栈2的底在V[m]，则栈满的条件是（）。 A. |top[2]-top[1]|=0 B. top[1]+1=top[2] C. top[1]+top[2]=m D. top[1]=top[2] 6. 执行完下列语句段后，i值为：（） int f(int x) { return ((x>0) ? x* f(x-1):2);} int i ; i =f(f(1)); A．2 B. 4 C. 8 D. 无限递归 7. 表达式3* 2^(4+2*2-6*3)-5求值过程中当扫描到6时，对象栈和算符栈为（），其中^为乘幂。 A. 3,2,4,1,1；(*^(+*- B. 3,2,8；(*^- C. 3,2,4,2,2；(*^(- D. 3,2,8；(*^(- 8. 用链接方式存储的队列，在进行删除运算时（）。 A. 仅修改头指针 B. 仅修改尾指针 C. 头、尾指针都要修改 D. 头、尾指针可能都要修改 9. 递归过程或函数调用时，处理参数及返回地址，要用一种称为（）的数据结构。 A．队列 B．多维数组 C．栈 D. 线性表 10．设C语言数组Data[m+1]作为循环队列SQ的存储空间， front为队头指针，rear为队尾指针，则执行出队操作的语句为（） A.front=front+1 B. front=（front+1）% m C.rear=(rear+1)%(m+1) D. front=(front+1)%(m+1) 11.循环队列的队满条件为 ( ) A. (sq.rear+1) % maxsize ==(sq.front+1) % maxsize; B. (sq.front+1) % maxsize ==sq.rear C. (sq.rear+1) % maxsize ==sq.front D.sq.rear ==sq.front
课下作业(三十二) 、选择题 1．哲学基本问题又称哲学的根本问题、哲学的最高问题。这一问题包括( ) ①物质和意识的辩证关系问题 ②思维和存在何者是本原的问题 ③思维和存在有没有同一性的问题 ④唯物主义和唯心主义关系问题 A ．①② B ．②③ C .③④ D .①③ 解析：选 B 。哲学基本问题包括两个方面的内容：一是思维和存在何者是本原的问题；二是思维和存在有没有同一性的问题，②③入选。 2. 唯物主义是哲学上两个敌对的基本派别之一，是同唯心主义相对立的思想体系。划分唯物 主义和唯心主义的唯一标准是( ) A .物质和意识的关系问题 B .客观与主观的关系问题 C .思维和存在何者是本原的问题 D ?思维和存在有没有同一性的问题 解析：选C。对思维和存在何者是本原问题的不同回答，是划分唯物主义和唯心主义的唯一 标准， C 入选。 3. “二月春分八月秋分昼夜不长不短；三年一闰五年再闰阴阳无差无错。”这副对联从一个侧面反映了( ) ①思维和存在具有同一性 ②认识与自然的吻合具有必然性 ③认识以实证和猜测为基础 ④意识活动具有主动创造性 A .①③ B .②④ C .①④ D .②③ 解析：选C o材料反映人们可以认识和把握自然界的运动规律,说明思维和存在具有同一性 反映了意识活动具有主动创造性，①④符合题意；认识与自然的吻合不具有必然性，②错误；实践是认识的基础，③错误。 4 .(2019河南中原名校联考)“为天地立心，为生民立命，为往圣继绝学，为万世开太平”是北宋张载的名言。由于其言简意宏，一直被人们传颂不衰。下列观点符合“为天地立心”的
是( ) ①形存则神存，形谢则神灭②吾心即是宇宙，宇宙即是吾心 ③思维着的精神是地球上最 美的花朵④“天不生仲尼，万古长如夜” A ．①② B ．①③ C .③④ D .②④ 解析：选C。“为天地立心”的意思是为天地确立一种核心价值理念，强调精神的作用，③ ④强调思维着的精神的作用，符合题意；①强调物质决定意识，②片面夸大意识的作用，均不合题意。 5.有位生物学学者认为，唯有生物学才能带领人类探究物种本源、生从何来死往何方等问题，他确信构成生物的眼见为实的物质比辩证唯物主义判断猜想的物质还正确。这种认识( ) ①没弄清辩证唯物主义的物质概念与构成生物的物质之间的关系 ②坚持了唯物主义根本方向，但属于古代朴素唯物主义的思想 ③犯了近代形而上学唯物主义错误，具有机械性、形而上学性 ④是在自然科学基础上对辩证唯物主义和历史唯物主义的发展 A .①② B .①③ C .②③ D .③④ 解析：选B。材料中的生物学学者没有看到哲学对具体科学的意义，认为哲学中的物质是猜 想的，没有看到哲学中的物质与自然科学中的物质是共性与个性的关系，因而具有机械性、 形而上学性，①③正确，②④错误。 6.18世纪法国哲学家丹尼斯狄德罗认为：“自然界由数目无穷、性质不同的异质元素构成。” 这种观点( ) ①承认世界的物质性，但把物质归结为自然科学意义上的元素②建立在自然科学成就的基 础上，丰富和发展了唯物主义③坚持物质第一性，但对物质的认识没有科学依据④认为世界是物质的，正确揭示了物质世界的基本规律 A .①② B .③④ C .①③ D .②④ 解析：选A。“狄德罗认为：‘自然界由数目无穷、性质不同的异质元素构成。'” 这种观点承认世界的物质性，但把物质归结为自然科学意义上的元素，①正确；狄德罗生活在18世纪，其观点建立在自然科学成就的基础上，丰富和发展了唯物主义，属于近代形而上学唯物主义，②入选；③④ 说法错误。 7 ?“宇宙创造过程中，上帝没有位置……没有必要借助上帝来为宇宙按下启动键”。这是斯
温馨提示： 此套题为Word版，请按住Ctrl,滑动鼠标滚轴，调节合适的观看比例，答案解析附后。 课后巩固作业（十九） (30分钟50分) 一、选择题(每题4分，共16分) 1.下列试验中，是古典概型的是( ) (A)发射一颗卫星能否成功 (B)从高一(18)班60名同学中任选一人测量其身高 (C)抛掷一枚骰子，出现1点或2点 (D)射击选手射击一次，恰中靶心 2.(2011·温州高一检测)抛掷两个骰子,则两个骰子点数之和大于4的概率为 ( ) (A)13 18 (B)8 9 (C)7 12 (D)5 6 3.从{1,2,3,4,5}中随机选取一个数为a，从{1,2,3}中随机选取一个数为b，则 b>a的概率是( ) (A)4 5 (B)3 5 (C) 2 5 (D)1 5 4.用1，2，3，4这四个数字，组成比2 000大且无重复数字的四位数的概率是 ( ) (A)1 4 (B)1 2 (C)3 4 (D)1 3 二、填空题(每题4分，共8分) 5.(2011·江苏高考)从1，2，3，4这四个数中一次随机取两个数，则其中一个
数是另一个的两倍的概率是_____. 6.(2011·永定高二检测)扔两枚骰子出现的点数为m,n，以(m,n)为坐标的点出现在x2+y2=16内的概率为_____. 三、解答题(每题8分，共16分) 7.一个袋中装有四个形状大小完全相同的球，球的编号分别为1，2，3，4. (1)从袋中随机抽取两个球，求取出的球的编号之和不大于4的概率； (2)先从袋中随机取一个球，该球的编号为m，将球放回袋中，然后再从袋中随机取一个球，该球的编号为n，求n 第三章栈和队列练习题 一、单项选择题 1．一个顺序栈一旦被声明，其占用空间的大小（）。 A．已固定B．可以改变C．不能固定D．动态变化 2．链栈和顺序栈相比，有一个比较明显的缺点，即（）。 A．插入操作更加方便B．通常不会出现栈满的情况 C．不会出现栈空的情况D．删除操作更加方便 3．用单链表表示的链式队列的队头在链表的（）位置。 A．链头B．链尾C．链中D．任意位置 4．在解决计算机主机与打印机之间速度不匹配问题时通常设置一个打印数据缓冲区，主机将要输出的数据依次写入缓冲区中，而打印机则从缓冲区中取出数据打印，该缓冲区应该是一个（）结构。 A．堆栈B．队列C．数组D．先性表 5．若已知一个栈的入栈序列是1，2，3，…，30，其输出序列是p1,p2,p3,…p n，若p1=30，则p10为（）。 A．11 B．20 C．19 D．21 6．循环队列A[m] 存放其元素，用front和rear分别表示队头及队尾，则循环队列满的条件是（）。 A．（rear+1)%m=front B．rear =front+1 C．rear=front D．（rear+1)%m-1=front 7．在一个栈顶指针为top的链栈中，将一个p指针所指的结点入栈，应执行（）。 A．top->next=p; B．p->next=top->next; top->next=p; C．p->next=top; top=p; D．p->next=top->next; top=top->next; 8．在一个栈顶指针为top的链栈中删除一个结点时，用x保存被删结点的值，则执行（）。 A．x=top;top=top->next; B．x=top->data; 人教版二年级下册语文 每课作业 HEN system office room 【HEN16H-HENS2AHENS8Q8-HENH1688】 1、找春天 一、看拼音写词语。 tuō xiàjiědònɡxī shuǐmián yī tàn tóu yáo tóu?yě huā duǒcánɡ 二、按课文内容填空。 1、春天来了！我们几个孩子，_______棉袄，________家门，________田野，去_______春天。春天像个___________，遮遮掩掩，躲躲藏藏。我们________地找啊，找啊。 2、春天来了！我们______到了她，我们______到了她，我们______到了她，我们______到了她。她在柳枝上_________，在风筝尾巴上_________；她在喜鹊、杜鹃__________，在桃花、杏花__________…… 三、填空。 藏藏丁丁遮遮 慌慌清清摇摇 四、照样子写词语。 遮掩遮遮掩掩认真 开心（） （）（） 五、在正确读音下面画横线。 1、我家院子里有几（jǐ jī）只小鸡，这些小鸡真可爱！ 2、我家的客厅里的茶几（jǐ jī）上有两杯水。 ★照样子，写句子。 小草从地下探出头来，那是春天的眉毛吧？ ，是 2、古诗两首 一、看拼音写词语。 Wèi lái zhuī gǎn shūdiàn kūhuáng guāng róng yěcài zhù sù gāo shāo 二、抄写古诗《草》 题目： 作者：三、比一比，组词语。 未（）烧（）枯（）徐（） 末（）浇（）姑（）除（） ★这两首诗都是描写季景色的。 ★《草》是朝大诗人写的，诗中“， 。”句最为有名，它描写了草顽强的生命力。诗中还有一对反义词，分别是________和________。★《宿新市徐公店》描写了种景物，分别是 。诗中最有意思的一句 是、 。 3、笋芽儿 一、拼一拼，写一写。 shì jiè sǔn yá hūhuàn shān gāng hōng dòng 二、读一读，并照样子，写一写。 啊，多么明亮、多么美丽的世界呀！ 三、按课文内容填空。 1、笋芽儿被叫醒了。她（）眼睛，（）懒腰，（）四周一片漆黑，撒娇地说：“是谁在叫我呀” 2、春雨姑娘（）着她，（）着她。太阳公公（）着她，（）着她。笋芽儿脱下一件件衣服，长成了一株（）的竹子。她站在山冈上，（）地喊着：“我长大啦！”四、比一比，再组词。 岗（）界（）笋（）牙（）喊 （）呼（） 刚（）介（）笛（）芽（）减 （）乎（） 部编版三年级语文下册同步练习 20. 肥皂泡 一、看拼音写词语。 féi zào cháng láng mù wǎn tòu míng jiāo ruǎn yǎng tóu yí chuàn fēi yuè yīng ér xī wàng 二、给下列加点字选择正确的读音，打“√”。 1、几个同学散．（sǎn sàn）漫得在操场上散．（sǎn sàn）步。 2、若用扇．(shān shàn)子在下面轻轻地扇．(shān shàn)送,有时它能飞得很高很高。 三、比一比，再组词。 皂（）透（）婴（）娇（）希（） 泉（）诱（）耍（）骄（）杀（） 四、照样子，完成练习。 例：无声地散裂无声地（）无声地（） 例：轻轻地扇轻轻地（）轻轻地（） 例：颤巍巍（ABB式）（）（）（）（） 五、我会查字典，给加点字选择正确的解释。 “仰”字按部首查字法应先查（）部，再查（）画。按音序查字法应先查大写字母（），再查音节（）。“仰”字在字典里的解释有：①脸向上，与“俯”相对；②敬慕；③依赖；给下列加点字选择正确的解释，填序号。 仰．起头（）久仰．大名（）仰．仗（） 六、择合适的词语填空。（填序号） ①颤巍巍②软悠悠③轻飘飘④慢腾腾 1.不知为什么，我这几天头晕眼花，走起路来感觉________的。 2.轻轻地一提，那轻圆的球儿便从管上落了下来，_______地在空中飘游。 3.他做事总是像老牛拉破车，_______的。 4.有时吹得太大了，扇得太急了，这脆薄的球，会扯成长圆的形式，______的，光影零乱。 七、按要求完成句子练习。 1. 把句子写具体。 ①薄球就散裂了。___________________________________________________________ ②浮光在球面上乱转。______________________________________________________ 2.我把用剩的碎肥皂放在一只小木碗里。（改为“被”字句） ____________________________________________________________________________ 3.小时候，我喜欢玩吹泡泡、滚铁环、西瓜等游戏。（修改病句） ___________________________________________________________________________ 七、阅读课文片段,完成练习 方法是把用剩的碎肥皂放在一只小木碗里，加上点水，（），使它融化，然后 ．．用一 支竹笔的套管，蘸上那黏稠的肥皂水，（）地吹起，吹起一个（）的网球大小 的泡儿，再．（）地一提，那轻圆的球儿，便从管上落了下来，（）地在空中飘游。若用扇子在下面（）地扇送，有时它能飞得很高很高。 1.根据课文内容填空。 2.这是写（）肥皂泡和（）肥皂泡的过程。 3.用“”画出做肥皂水方法的句子。 4.用“先……然后……再……”说一说吹肥皂泡的过程。 . 八、快乐阅读。 种一片树叶 冰心 埋下一片树叶，固执地相信它终会长成一棵参天大树。这便是儿时最美的梦。 我4岁那年的秋天，枯黄的叶子从高高的树枝上飘落，正在院中玩耍的我俯身拾起一片， 觉得很美。玩赏了半天，我忽发一个奇怪的想法：这个曾经是树伯伯身上一部分的叶，把它 种进土里之后，必定可以长出一棵同样的大树! 于是我捡了许多片叶子，虔诚地跪在地上挖了个小坑，把树叶全埋到了土里。就像妈妈 生下了我，我也会渐渐长大—样，我坚定地相信我的梦马上可以实现。 我天天蹲在种树叶的地方等待我的大树，直到大雪纷飞。我想叶子大概怕冷，所以不敢 出来，等明年开春，一定会长得更好!我依旧固执地坚守着自己的梦，直到燕子衔泥，杨树吐 必修2 Unit 1 课下作业（一~三） 课下作业（一）考点过关针对练 Ⅰ.单词拼写 1．Jim insisted that the book Mr.Black referred to was worth (值得的) reading. 2．She took one look at the horse and her heart sank (下沉)． 3．It was not until he removed (摘掉) his sunglasses that I recognized him. 4．I'll be waiting for you at the entrance (入口) to Guangzhou station. 5．The coal industry is now barely half its former (以前的) size. 6．The door opened and in came a troop of children in all sorts of fancy (奇特的) dresses. 7．Some animals are hunted illegally, so they become rare (珍贵的；稀有的)． 8．To make my room look nicer, I had the walls decorated (装饰) with paper cuts last year. Ⅱ.语境语法填空 1．?Having_removed (remove) from his hometown to the city, Zhang Qiang didn't know what ?to_do (do) at first.Under the guidance of his friend Li Ping, he made ?a fortune by doing business.He launched a campaign which ?was_designed (design) to help those in need in return ?for the society.He has done so much for the poor in his community that we can't think ?highly (high) of him enough. 2．As is known to all, cultural relics belong ?to human beings rather than individuals, so they are well worth ?protecting (protect)．However, some people are in search ?of them and take possession of them illegally.Some of them have been damaged while only a few survive.Therefore, every one of us should make all efforts to protect them from ?being_destroyed (destroy)．There is no doubt ?that it is our duty to protect cultural relics. 3．The old piano I bought years ago took up too much room, so ?by the light of the room, I ?took (take) it apart.I sold it to a waste recycling center at a low price. Ⅲ.语境改错 1．文中共有3处错误，每句中最多有两处，请找出并改正。 After removed dirt from the vase, the expert was amazed to find that it survived the Tang Dynasty.The vase was so amazingly designed that it was very worth buying at such a reasonable price. 答案：第一句：removed→removing; survived后加from 第二句：very→well 2．文中共有3处错误，每句中最多有两处，请找出并改正。 习题三参考答案 备注: 红色字体标明的是与书本内容有改动的内容。 一、选择题 1.在栈中存取数据的原则是（ B ）。 A．先进先出 B. 先进后出 C. 后进后出 D. 没有限制 2．若将整数1、2、3、4依次进栈，则不可能得到的出栈序列是（ D ）。 A．1234 B. 1324 C. 4321 D. 1423 3．在链栈中，进行出栈操作时（B ）。 A．需要判断栈是否满 B. 需要判断栈是否为空 C. 需要判断栈元素的类型 D. 无需对栈作任何差别 4．在顺序栈中，若栈顶指针top指向栈顶元素的下一个存储单元，且顺序栈的最大容量是maxSize，则顺序栈的判空条件是（ A ）。 A．top==0 B.top==-1 C. top==maxSize D.top==maxSize-1 5．在顺序栈中，若栈顶指针top指向栈顶元素的下一个存储单元，且顺序栈的最大容量是maxSize。则顺序栈的判满的条件是（ C ）。 A．top==0 B.top==-1 C. top==maxSize D.top==maxSize-1 6．在队列中存取数据元素的原则是（ A ）。 A．先进先出 B. 先进后出 C. 后进后出 D. 没有限制 7．在循环顺序队列中，假设以少用一个存储单元的方法来区分队列判满和判空的条件，front和rear分别为队首和队尾指针，它们分别指向队首元素和队尾元素的下一个存储单元，队列的最大存储容量为maxSize，则队列的判空条件是（A ）。 A．front==rear B. front!=rear C. front==rear+1 D. front==(rear+1)% maxSize 8．在循环顺序队列中，假设以少用一个存储单元的方法来区分队列判满和判空的条件，front和rear分别为队首和队尾指针，它们分别指向队首元素和队尾元素的下一个存储单元，队列的最大存储容量为maxSize，则队列的判满条件是（D ）。 A．front==rear B. front!=rear C. front==rear+1 D. front==(rear+1)% maxSize 9.在循环顺序队列中，假设以少用一个存储单元的方法来区分队列判满和判空的条件，front和rear分别为队首 和队尾指针，它们分别指向队首元素和队尾元素的下一个存储单元，队列的最大存储容量为maxSize，则队列的长度是（C ）。 A．rear-front B. rear-front+1 C. (rear-front+maxSize)%maxSize D. (rear-front+1)%maxSize 10.设长度为n的链队列采用单循环链表加以表示，若只设一个头指针指向队首元素，则入队操作的时间复杂度 为（ B ）。 A．O(1) B．O(n) C．O(log2n) D．O(n2) 二、填空题 1.栈是一种操作受限的特殊线性表，其特殊性体现在其插入和删除操作都限制在表尾进行。允许插入和删除 操作的一端称为栈顶，而另一端称为栈底。栈具有后进先出的特点。 2.栈也有两种存储结构，一种是顺序存储，另一种是链式存储；以这两种存储结构存储的栈分别称为顺序 栈和链栈。 3.在顺序栈中，假设栈顶指针top是指向栈顶元素的下一个存储单元，则顺序栈判空的条件是 top==0 ; 栈顶 第三章栈和队列 一、判断题 1、链栈的初始化是指开辟足够多的结点，然后置栈顶指针为 NULL。（×） 2、递归定义的数据结构通常不需要用递归的算法来实现对它的操作。（×） 二、填空题 1、向一个链式栈插入一个新结点时，首先把栈顶指针的值赋给新结点的指针域，然后把新结点的存储位置赋给___栈顶指针_____。 2、迷宫问题是一个回溯控制的问题，最好使用____栈______的方法来解决。 3、有如下递归过程： Void Print(int w) { int i; if (w!=0) { Print(w?1); for (i=1;i<=w;i++) printf(“%3d”,w); printf(“\n”); } } 调用语句print(4)的结果是__________。 1 2 2 3 3 3 4 4 4 4 4、假设用循环单链表实现队列，若队列非空，且队尾指针为R, 则将新结点S加入队列时，需执行下面语句：_ S->next=R->next _________；___ R->next=S _______；R=S； 三、选择题 1、设有4个数据元素a1、a 2、a3和a4，对他们分别进行栈操作或队操作。在进栈或进队操作时，按a1、a2、a 3、a4次序每次进入一个元素。假设栈或队的初始状态都是空。 现要进行的栈操作是进栈两次，出栈一次，再进栈两次，出栈一次；这时，第一次出栈得到的元素是 A 2，第二次出栈得到的元素是 B 4；类似地，考虑对这四个数据元素进行的队操作是进队两次，出队一次，再进队两次，出队一次；这时，第一次出队得到的元素是 C 1，第二次出队得到的元素是 D 2。经操作后，最后在栈中或队中的元素还有 E 2个。 供选择的答案： A～D：①a1 ②a2 ③ a3 ④a4 E：①1 ②2 ③ 3 ④ 0 2、栈是一种线性表，它的特点是 A 2。设用一维数组A[1,…,n]来表示一个栈，A[n]为栈底，用整型变量T指示当前栈顶位置，A[T]为栈顶元素。往栈中推入（PUSH）一个新元素时，变量T的值 B 2；从栈中弹出（POP）一个元素时，变量T的值 C 1。设栈空时，有输入序列a，b，c，经过PUSH，POP，PUSH，PUSH，POP操作后，从栈中弹出的元素的序列是 D 6，变量T的值是 E 4。 供选择的答案： A：①先进先出②后进先出③进优于出④出优于进⑤随机进出 B，C：①加1 ②减1 ③不变④清⑤加2 ⑥减2 D：① a,b ②b,c ③c,a ④b,a ⑤ c,b ⑥a,c E：① n+1 ②n+2 ③ n ④ n-1 ⑤ n-2 3、在做进栈运算时，应先判别栈是否 A 2；在做退栈运算时，应先判别栈是否 B 1。当栈中元素为n个，做进栈运算时发生上溢，则说明该栈的最大容量为 C 2。 MATLAB 作业 1.构造矩阵A =[?718?3],B =[4257],C =[59 62 ] （1）试将A ·*B 与A*B 的结果相加，并找出相加后新矩阵中绝对值大于10的元素。 （2）组合成一个4×3的矩阵，第一列为按列顺序排列的A 矩阵元素，第二列为按列顺序排列的B 矩阵元素，第三列为按列顺序排列的C 矩阵元素。 解答： （1） 在matlab 上的程序如下： >> A=[-7,1;8,-3]; >> B=[4,2;5,7]; >> C=[5,9;6,2]; >> A.*B ans = -28 2 40 -21 >> A*B ans = -23 -7 17 -5 >> D=A.*B+A*B D = -51 -5 57 -26 >> D(find(D<-10|D>10)) ans = -51 57 -26 （2） 在matlab 上的程序如下： >> A=[-7,1;8,-3]; >> B=[4,2;5,7]; >> C=[5,9;6,2]; >> D=[A(:),B(:),C(:)] D = -7 4 5 8 5 6 1 2 9 -3 7 2 2、求解以下方程组的解（一组解即可）。 {4x +6y +3z =132x +3y +4z =9 解答： 在matlab 上的程序如下： >> A=[4,2;6,3;3,4]; >> A=A'; >> B=[13;9]; >> x=A\B x = 0 1.6667 1.0000 3、使用spdinag(B,d,m,n)命令创建4阶稀疏矩阵A,求其秩，并将A 转换为全矩阵C （其中矩阵B=[1;2;3;4],d=1）。 解答： 在matlab 上的程序如下： >> B=[1;2;3;4]; >> A=spdiags(B,1,4,4) A = (1,2) 2 (2,3) 3 (3,4) 4 >> sprank(A) ans = 3 >> full(A) ans = 0 2 0 0 0 0 3 0 0 0 0 4 0 0 0 0 4、求函数f (t )=1?12.5e ?t sin(2t +3.4)在t>0区间内的所有零点。 解答： 在matlab 上的程序如下： >> f=@(t)(1-12.5*exp(-t)*sin(2*t+3.4)); >> fplot(f,[0,10]); >> a=fzero(f,1) a = 1.6583 >> b=fzero(f,2) b = 1.6583 >> c=fzero(f,3) c = 1、让我们荡起双桨 一、基础擂台赛 1、照样子做一做 京（凉）（凉风） （惊）（惊吓） （）（）（）（）（）（）良西果 （）（）（）（）（）（）2、选字填空 做作 工（）（）工（）事（）业 课棵 （）桌一（）（）本几（）树 3、句式仿写 例：水中鱼儿望着我们，悄悄地听我们愉快歌唱。 4、在括号里填上合适的词。 美丽的（）幸福的（）（）地飘荡 凉爽的（）亲爱的（）（）地听 二、作业超市 选择你喜欢的题目做一做！ 1、课文回放 “红领巾迎着太阳”一句中的“红领巾”指____________________________。 2、记录生活试着写几句描写我们课外生活的话，用上“欢乐、伙伴、愉快、尽情”等课文中的词语，相信你一定会写得很精彩。 2、友谊桥 一、基础擂台赛 1、填空 傲慢的近义词是（）它的反义词是（） 他傲慢地说：“（）。” 2、短文共有（）个自然段。从第一自然段至第六自然段描写蜡笔娃娃的________，第7、8自然段描写蜡笔娃娃共同。 3、短文说蜡笔娃娃画的彩虹是他们架起的友谊桥，为什么？选择正确的答案打“√”。 （1）彩虹像一座弯弯的小桥，太美丽。（） （2）彩虹是蜡笔娃娃团结协作，共同画的，彩虹的样子也像桥，表现了他们之间的友谊。（） 二、读下面一段话，完成练习。 看，蓝蓝的天上挂着红太阳，阳光下的青山格外美丽；小溪像白色的飘带，溪边花红柳绿；山下是一望无际的麦田，麦田里翻滚着金色的麦浪…… 1、找出这段话中描写颜色的词语，用“△”做上记号。 2、背诵这段话，看谁背得又快又准确。 3、“一望无际”是说麦田，跟“格外”意思相近的词语有、。 4、你见过小溪吗？学着课文中的方法写一写，它还像什么？ 5、（选做题）认真读上面一段文字，边读边想，把想到的画面画下来。 课下作业(六) 一、选择题 1．国家利率政策的变化会影响到居民的生活。在居民收入一定的情况下，下图中正确反映消费与储蓄之间关系的是() 解析：选C。在收入一定的情况下，消费与储蓄之间成反比关系，B错误；由于人们不可能把所有收入都用于消费或储蓄，故A、D均错误，C正确。 2．某银行将信用卡业务放入“手机银行”，通过手机上的客户端向客户提供各项银行业务和个性化的定制信息服务(如金融产品推荐)。这一举措有利于() ①降低银行的经营成本②扩展银行的业务范围③降低银行的经营风险④提高银行的服务品质 A．①④B．①② C．②③D．②④ 解析：选A。题目中，某银行将信用卡业务放入“手机银行”，通过手机上的客户端向客户提供各项银行业务和个性化的定制信息服务(如金融产品推荐)。这一举措有利于降低银行的经营成本，提高银行的服务品质，①④入选；②③表述与题意不符。 3．由于银行储蓄存款利率较低，银行理财产品受到更多人青睐。某商业银行推出的一款期限为73天的理财产品，预期年化收益率为3.6%。老王购买了8万元该理财产品，其预期收益约为() A．576元B．360元 C．175元D．35元 解析：选A。某商业银行推出的一款期限为73天的理财产品，预期年化收益率为3.6%。老王购买了8万元该理财产品，其预期收益约为：80 000×3.6%÷365×73＝576元，A正确。4．2019年4月25日，中共中央政治局就维护国家金融安全进行第四十次集体学习，提出金融活，经济活；金融稳，经济稳。下列有利于维护金融安全的是() A．加快资本市场建设，推动实体经济避实向虚 B．央行实施紧缩的货币政策，不断提高存贷款利率 C．大力发展外向型经济，推动金融企业“走出去” D．建立健全金融机构和金融监管的体制机制 解析：选D。加快资本市场建设，推动实体经济避实向虚，这样不利于维护金融安全，A错误；现阶段，我国实行积极的财政政策和稳健的货币政策，B不利于维护金融安全，排除；我国实行对外开放，发展对外经济关系，必须始终坚持独立自主、自力更生的原则，要在立 部编版六下课堂作业本答案 第一单元 第1课北京的春节 2、读句子，根据拼音写词语 万象更新彼此贺年燃放鞭炮通宵间断 3、读一读，选一选。 （1）②（2）③ 4、根据课文内容填空。 时间读者对老北京人过春节的风俗习惯既有了较为全面的了解，同时对重点的风俗习惯也有了较为深刻的印象。 5、阅读课文片段，完成练习。 （一） （1）气味色彩对联年画鞭炮 （2）想让读者体会人们对除夕的重视，感受除夕佳节饱含的浓浓亲情以及北京春节浓郁的民俗文化。 （二） （1）用各种干果与蜜饯掺和而成的食物各种零食风筝、空竹、口琴等玩具。 （2）增加了语言的地方风味，富有生活气息。 （3）略 第2课腊八粥 2.读句子，根据拼音写词语。 沸腾腊八粥惊异肿胀感觉解释 3. 根据课文内容填空。 喝粥兴奋急切惊异 喝粥 使文章主次分明，重点突出，既突出了八儿对腊八粥的喜爱和渴昐，给人留下了深刻的印象，也反映出一家人浓浓的亲情以及腊八粥带给人们的幸福和满足。 4. 照样子摘录文中细腻描写腊八粥的句子，读一读，写下自己的感受。 摘录：把小米、饭豆、枣、栗、白糖、花生仁合拢来，糊糊涂涂煮成一锅，让它在锅中叹气似的沸腾着,单看它那叹气样儿，闻闻那种香味,就够咽三口以上的唾沫了，何况是，大碗大碗地装着，大匙大匙朝嘴里塞灌呢! 感受：从原材料、粥的浓稠度、煮粥时发出的声音等方面对腊八粥进行了生动细致的描写，让人仿佛看到了正在锅中翻滚着的腊八粥。 摘录：“锅中的粥，有声无力的叹气还在继续”“栗子跌进锅里，不久就得粉碎”。感受：这些细腻的描写，使腊八粥仿佛有了生命一般，从字里行间跳出 来，香喷喷、甜腻腻地呈现在我们面前。 5.阅读课文片段，完成练习。 （1）根据片段内容填空。 提到腊八粥，嘴里就立时生出甜腻的感觉 把小米、饭豆、枣、栗、白糖、花生仁合拢来，糊糊涂涂煮成一锅 气香 （2）煮粥时发出的声音腊八粥给人们带来的巨大吸引力，以及大家对腊八粥深深的喜爱 （3） 提起山粉饺，不论是白发苍苍的老人，还是蹒跚学步的小孩都忍不住直流口水。由番薯粉和芋头粉做成的山粉皮包裹着肉馅，在滚开的水里上下翻腾。锅里的山粉饺逐渐变得晶莹透亮，腾腾的热气散发着诱人的香味。闻着那股香味就让人拇指大动，恨不得立马吃上三大碗呢！ 第3课古诗三首 2、根据课文内容填空 （1）春城无处不飞花轻烟散入五侯家禁生火,吃冷食 （2）牛郎织女盈盈一水间，脉脉不得语 （3）不知秋思落谁家思乡、思亲 举头望明月，低头思故乡。 春风又绿江南岸，明月何时照我还。 3、下面的古诗分别写了哪个传统节日和哪些习俗？照样子，连一连。 《元日》—春节—放鞭炮、贴桃符等 《清明》—清明节—扫墓 《十五夜望月》—中秋节—赏月 《九月九日忆山东兄弟》—重阳节—登高、插茱萸 第三章栈与队列练习题 一、选择题 1、栈结构通常采用的两种存储结构是（ A ）。 A、顺序存储结构和链表存储结构 B、散列和索引 C、链表存储结构和数组 D、线性链表和非线性存储 2、设栈ST用顺序存储结构表示，则栈ST为空的条件是（B） A、ST.top-ST.base<>0 B、ST.top-ST.base==0 C、ST.top-ST.base<>n D、ST.top-ST.base==n 3、向一个栈顶指针为HS的链栈中插入一个s结点时，则执行（） A、HS->next=s; B、s->next=HS->next;HS->next=s; C、s->next=HS;HS=s; D、s->next=HS;HS=HS->next; 4、从一个栈顶指针为HS的链栈中删除一个结点，用x保存被删除结点的值，则执行（C） A、x=HS;HS=HS->next; B、HS=HS->next;x=HS->data; C、 x=HS->data;HS=HS->next; D、s->next=Hs;Hs=HS->next; 7、一个队列的入列序列是1，2，3，4，则队列的输出序列是（B ）//尾插入元素，头删除元素。 A、4，3，2，1 B、1，2，3，4 C、1，4，3，2 D、3，2，4，1 9、循环队列SQ采用数组空间SQ.base[0,n-1]存放其元素值，已知其头尾指针分别是front和rear，则判定此循环队列为满的条件是（C）//不懂啊！！！ A、Q.front==Q.rear B、Q.front!=Q.rear C、Q.front==(Q.rear+1)%n D、Q.front!=(Q.rear+1)%n 11、用单链表表示的链式队列的队头在链表的（A）位置 A、链头 B、链尾 C、链中 12、判定一个链队列Q（最多元素为n个）为空的条件是（ A） A、Q.front==Q.rear B、Q.front!=Q.rear C、Q.front==(Q.rear+1)%n D、Q.front!=(Q.rear+1)%n 14、在一个链队列Q中，删除一个结点需要执行的指令是（C） A、Q.rear=Q.front->next; B、Q.rear->next=Q.rear->next->next; C、 Q.front->next=Q.front->next->next; D、Q.front=Q.rear->next; 15、用不带头结点的单链表存储队列，其队头指针指向队头结点，队尾指针指向队尾结点，则在进行出队操作时（D） A、仅修改队头指针 B、仅修改队尾指针 C、队头尾指针都要修改 D、队头尾指针都可能要修改。 16、栈和队列的共同点是（C） A、都是先进后出 B、都是先进先出 C、只允许在端点处插入和删除元素 D、没有共同点 18、设有一顺序栈S，元素s1,s2,s3,s4,s5,s6依次进栈，如果6个元素出栈的顺序是s2,s3,s4,s6,s5,s1，则栈的容量至少应该是（B） A、2 B、 3 C、 5 D、 6 20、设有一顺序栈已经含有3个元素，如图3.1所示元素a4正等待进栈。下列不可能出现的出栈序列是（A） 0 maxsize-1第三章栈和队列练习题
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