课时作业5

课时作业(五)1．在正方体ABCD －A 1B 1C 1D 1中，E 是上底面A 1B 1C 1D 1的中心，则AC 1与CE 的位置关系是( )A ．重合B ．垂直C ．平行D ．无法确定 答案 B2．已知斜三棱柱ABC －A 1B 1C 1中，底面ABC 是等腰直角三角形，AB ＝AC ＝2，CC 1＝2，AA 1与AB ，AC 都成60°角，则异面直线AB 1与BC 1所成角的余弦值为( ) A.14 B.155 C.105 D.16 答案 D3.如图，正方体ABCD －A 1B 1C 1D 1的棱长为1，AM →＝12MC 1→，点N 为B 1B 的中点，则|MN →|等于( )A.216 B.66 C.156 D.153 答案 A4.如图所示，在正方体ABCD －A 1B 1C 1D 1中，O 是底面正方形ABCD 的中心，M 是DD 1的中点，N 是A 1B 1的中点，则直线ON 与AM 的位置关系是( )A ．平行B ．垂直C ．相交但不垂直D ．无法判断答案 B5．对于空间任意一点O 和不共线的三点A ，B ，C ，有OP →＝xOA →＋yOB →＋zOC →(x ，y ，z ∈R )，则“x ＝2，y ＝－3，z ＝2”是“P ，A ，B ，C 四点共面”的( ) A ．必要不充分条件 B ．充分不必要条件 C ．充要条件 D ．既不充分也不必要条件 答案 B解析 由题意，{OA →，OB →，OC →}构成空间的一个基底，OP →＝xOA →＋yOB →＋zOC →(x ，y ，z ∈R )，则P ，A ，B ，C 四点共面等价于x ＋y ＋z ＝1.若x ＝2，y ＝－3，z ＝2，则x ＋y ＋z ＝1，所以P ，A ，B ，C 四点共面．若P ，A ，B ，C 四点共面，则x ＋y ＋z ＝1，不能得到“x ＝2，y ＝－3，z ＝2.所以“x ＝2，y ＝－3，z ＝2”是“P ，A ，B ，C 四点共面”的充分不必要条件． 6.如图，在大小为45°的二面角A －EF －D 中，四边形ABFE ，CDEF 都是边长为1的正方形，则B ，D 两点间的距离是( )A. 3B. 2C ．1 D.3－ 2 答案 D解析 {BF →，FE →，ED →}构成空间的一个基底，因为BD →＝BF →＋FE →＋ED →，所以|BD →|2＝|BF →|2＋|FE→|2＋|ED →|2＋2BF →·FE →＋2FE →·ED →＋2BF →·ED →＝1＋1＋1－2＝3－2，故|BD →|＝3－ 2.7．已知空间四边形ABCD 的各边和对角线的长都等于a ，点M ，N 分别是AB ，CD 的中点，则MN ________AB (填“∥”或“⊥”)． 答案 ⊥8．已知V 为矩形ABCD 所在平面外一点，且VA ＝VB ＝VC ＝VD ，若VP →＝13VC →，VM →＝23VB →，VN →＝23VD →，则VA 与平面PMN 的位置关系是________．答案 平行解析 设VA →＝a ，VB →＝b ，VC →＝c ，则{a ，b ，c }构成空间的一个基底，VD →＝a ＋c －b .由题意知PM →＝23b －13c ，PN →＝23VD →－13VC →＝23a －23b ＋13c .因此VA →＝32PM →＋32PN →，所以VA →，PM →，PN →共面．又VA ⊄平面PMN ，所以VA ∥平面PMN .9.如图，在正方体ABCD －A 1B 1C 1D 1中，P 是DD 1的中点，O 是底面ABCD 的中心．求证：B 1O ⊥平面P AC .解析 如图，连接BD ，则BD 过点O ，令AB →＝a ，AD →＝b ，AA 1→＝c ， 设|a |＝|b |＝|c |＝1，∵AC →＝AB →＋AD →＝a ＋b ，OB 1→＝OB →＋BB 1→＝12DB →＋BB 1→＝12(AB →－AD →)＋BB 1→＝12a －12b ＋c .∴AC →·OB 1→＝(a ＋b )·⎝⎛⎭⎫12a －12b ＋c ＝12|a |2＋12a ·b －12a ·b －12|b |2＋a ·c ＋b ·c ＝12－12＝0. ∴AC →⊥OB 1→，即AC ⊥OB 1.又AP →＝AD →＋12DD 1→＝b ＋12c ，∴OB 1→·AP →＝⎝⎛⎭⎫12a －12b ＋c ·⎝⎛⎭⎫b ＋12c ＝12a ·b －12|b |2＋c ·b ＋14a ·c －14b ·c ＋12|c |2＝－12＋12＝0， ∴OB 1→⊥AP →， 即OB 1⊥AP .又AC ∩AP ＝A ，AC ，AP ⊂平面P AC ，∴OB 1⊥平面P AC .10．在正方体ABCD －A 1B 1C 1D 1中，已知E ，F ，G ，H 分别是CC 1，BC ，CD 和A 1C 1的中点．证明：(1)AB 1∥GE ，AB 1⊥EH ； (2)A 1G ⊥平面EFD .证明 (1)如图，设正方体棱长为1，AB →＝i ，AD →＝j ，AA 1→＝k ，则{i ，j ，k }构成空间的一个单位正交基底.AB 1→＝AB →＋BB 1→＝i ＋k ，GE →＝GC →＋CE →＝12i ＋12k ＝12AB 1→，∴AB 1∥GE .EH →＝EC 1→＋C 1H →＝12k ＋⎝⎛⎭⎫－12(i ＋j ) ＝－12i －12j ＋12k ，∵AB 1→·EH →＝(i ＋k )·⎝⎛⎭⎫－12i －12j ＋12k ＝－12|i |2＋12|k |2＝0，∴AB 1⊥EH .(2)A 1G →＝A 1A →＋AD →＋DG →＝－k ＋j ＋12i .DF →＝DC →＋CF →＝i －12j ，DE →＝DC →＋CE →＝i ＋12k .∴A 1G →·DF →＝⎝⎛⎭⎫－k ＋j ＋12i ·⎝⎛⎭⎫i －12j ＝－12|j |2＋12|i |2＝0，∴A 1G ⊥DF .A 1G →·DE →＝⎝⎛⎭⎫－k ＋j ＋12i ·⎝⎛⎭⎫i ＋12k ＝－12|k |2＋12|i |2＝0，∴A 1G ⊥DE .又DE ∩DF ＝D ，DE ，DF ⊂平面EFD ， ∴A 1G ⊥平面EFD .11．在棱长为1的正方体ABCD －A 1B 1C 1D 1中，M ，N ，H 分别在棱BB 1，BC ，BA 上，且满足BM →＝34BB 1→，BN →＝12BC →，BH →＝12BA →，O 是平面B 1HN 、平面ACM 与平面B 1BDD 1的一个公共点，设BO →＝xBH →＋yBN →＋zBM →，则x ＋y ＋3z ＝( ) A.105 B.125 C.145 D.165 答案 C解析 {BH →，BN →，BM →}构成空间的一个基底，如图，设Q 为AC 与BD 的交点，P 为BQ 的中点，连接MQ ，B 1P ，O 为MQ 与B 1P 的交点．过P 作PT ∥MQ 交BB 1于T .则T 为BM 的中点，所以MT ＝12BM ＝12×34BB 1＝12×34×4MB 1＝32MB 1.所以B 1O →＝23OP →，因此BO→＝35BB 1→＋25BP →＝35·43BM →＋25·12(BH →＋BN →)＝45BM →＋15BH →＋15BN →，因为BO →＝xBH →＋yBN →＋zBM →，所以z ＝45，x ＝15，y ＝15，所以x ＋y ＋3z ＝145.12.【多选题】如图，三棱柱ABC －A 1B 1C 1中，底面边长和侧棱长都等于1，∠BAA 1＝∠CAA 1＝60°.设AA 1→＝a ，AB →＝b ，AC →＝c ，则( )A.BC 1→＝a ＋b ＋cB ．|BC 1→|＝ 2 C ．BC 1⊥A 1B 1D ．异面直线AB 1与BC 1所成角的正切值为 5 答案 BCD解析 以{a ，b ，c }为空间的一个基底，BC 1→＝BB 1→＋B 1C 1→＝BB 1→＋A 1C 1→－A 1B 1→＝AA 1→＋AC →－AB→＝a ＋c －b ，A 不正确．因为a ·b ＝|a |·|b |cos ∠BAA 1＝1×1×cos 60°＝12，同理可得a ·c ＝b ·c ＝12，所以|BC 1→|＝（a ＋c －b ）2＝a 2＋c 2＋b 2＋2a ·c －2a ·b －2c ·b ＝1＋1＋1＋1－1－1＝2，B 正确．因为A 1B 1→＝AB →＝b ，所以A 1B 1→·BC 1→＝b ·(a ＋c －b )＝b ·a ＋b ·c －b 2＝12＋12－1＝0，C 正确．因为AB 1→＝a ＋b ，所以|AB 1→|＝（a ＋b ）2＝a 2＋b 2＋2a ·b ＝1＋1＋1＝3，因为AB 1→·BC 1→＝(a ＋b )·(a ＋c －b )＝a 2＋a ·c －a ·b ＋b ·a ＋c ·b －b 2＝1＋12－12＋12＋12－1＝1.所以cos〈AB 1→，BC 1→〉＝AB 1→·BC 1→|AB 1→||BC 1→|＝13×2＝66，sin 〈AB 1→，BC 1→〉＝1－⎝⎛⎭⎫662＝306，tan 〈AB 1→，BC 1→〉＝ 5.所以异面直线AB 1与BC 1所成角的正切值为5，D 正确．13.【多选题】如图，已知斜三棱柱ABC －A 1B 1C 1中，∠BAC ＝π2，∠BAA 1＝2π3，∠CAA 1＝π3，AB ＝AC ＝1，AA 1＝2，点O 是B 1C 与BC 1的交点．则下列结论正确的是( )A.AO →＝12(AB →＋AC →＋AA 1→) B ．|AO →|＝32C ．AO ⊥BCD ．平面ABC ⊥平面B 1BCC 1 答案 AD解析 AO →＝AB →＋BO →＝AB →＋12(BC →＋BB 1→)＝AB →＋12(AC →－AB →＋AA 1→)＝12(AB →＋AC →＋AA 1→)，A 正确．设AB →＝a ，AC →＝b ，AA 1→＝c ，则{a ，b ，c }构成空间的一个基底．|AO →|2＝⎣⎡⎦⎤12（a ＋b ＋c ）2＝14(a 2＋b 2＋c 2＋2a ·b ＋2b ·c ＋2a ·c )＝14(1＋1＋4＋0＋2×1×2×cos π3＋2×1×2×cos 2π3)＝32，所以|AO →|＝62，B 不正确．因为BC →＝b －a ，所以AO →·BC →＝12(a ＋b ＋c )·(b －a )＝1≠0，C 不正确．如图，取BC 的中点E ，连接AE ，则AE →＝12(AB →＋AC →)＝12(a ＋b )．因为AB ＝AC ，E 为BC 的中点，所以AE ⊥BC .又AE →·BB 1→＝12(a ＋b )·c ＝12(1×2×cos 2π3＋1×2×cos π3)＝0，所以AE ⊥BB 1.因为BC ∩BB 1＝B ，BB 1，BC ⊂平面B 1BCC 1，所以AE ⊥平面B 1BCC 1.又AE ⊂平面ABC ，所以平面ABC ⊥平面B 1BCC 1，D 正确．14．空间四边形OABC 的各边及对角线长均为2，E 是AB 的中点，F 在OC 上，且OF →＝2FC →.(1)用{OA →，OB →，OC →}表示EF →＝________；(2)向量OE →与向量BF →所成角的余弦值为________．答案 (1)－12OA →－12OB →＋23OC → (2)－52142解析 (1){OA →，OB →，OC →}构成空间的一个基底，因为E 是AB 的中点，F 在OC 上，且OF →＝2FC →，所以OE →＝12(OA →＋OB →)，OF →＝23OC →，于是EF →＝OF →－OE →＝ 23OC →－12(OA →＋OB →)＝－12OA →－12OB →＋23OC →.(2)由(1)得OE →＝12(OA →＋OB →)，BF →＝OF →－OB →＝23OC →－OB →，因此|OE →|＝12|OA →＋OB →|＝12×4＋4＋2×2×2×12＝3，|BF →|＝⎪⎪⎪⎪23OC →－OB →＝49×4＋4－43×2×2×12＝273，又因为OE →·BF →＝12(OA →＋OB →)·⎝⎛⎭⎫23OC →－OB →＝－53，所以向量OE →与向量BF →所成角的余弦值cos 〈OE →，BF →〉＝OE →·BF →|OE →||BF →|＝－533×273＝－52142.15．在棱长为2的正四面体ABCD 中，点M 满足AM →＝xAB →＋yAC →－(x ＋y －1)AD →，点N 满足BN →＝λBA →＋(1－λ)BC →，当AM ，BN 最短时，AM →·MN →等于( )A ．－43 B.43C ．－13 D.13答案 A16.在如图所示的平行六面体ABCD －A 1B 1C 1D 1中，已知AB ＝AA 1＝AD ，∠BAD ＝∠DAA 1＝60°，∠BAA 1＝30°，N 为A 1D 1上一点，且A 1N ＝λA 1D 1.若BD ⊥AN ，则λ的值为________．答案3－11.如图，直三棱柱ABC －A 1B 1C 1中，∠ABC ＝120°，AB ＝2，BC ＝CC 1＝1，则异面直线AB 1与BC 1所成角的余弦值为( )A.32 B.155 C.105 D.33 答案 C 解析 设BA →＝a ，BC →＝b ，BB 1→＝c ，则|a |＝2，|b |＝|c |＝1， AB 1→＝c －a ，BC 1→＝b ＋c ，a ·b ＝|a |·|b |cos ∠ABC ＝2×1×cos 120°＝－1，a ·c ＝b ·c ＝0， |AB 1→|＝|c －a |＝5，|BC 1→|＝|b ＋c |＝2， AB 1→·BC 1→＝(c －a )·(b ＋c )＝b ·c ＋c 2－a ·b －a ·c ＝0＋1－(－1)－0＝2，所以cos 〈AB 1→，BC 1→〉＝AB 1→·BC 1→|AB 1→|·|BC 1→|＝25×2＝105.所以异面直线AB 1与BC 1所成角的余弦值为105. 2.如图，在空间四边形OABC 中，OA ＝8，AB ＝6，AC ＝4，BC ＝5，∠OAC ＝45°，∠OAB ＝60°，则OA 与BC 所成角的余弦值为( )A.3－225B.2－26C.12D.32 答案 A解析 因为OA →·BA →＝8×6×cos 60°＝24，OA →·AC →＝8×4×cos 135°＝－16 2.设异面直线OA与BC 的夹角为θ，则cos θ＝|OA →·BC →||OA →||BC →|＝|OA →·（BA →＋AC →）||OA →||BC →|＝24－1628×5＝3－225.3.【多选题】如图，一个结晶体的形状为平行六面体ABCD －A 1B 1C 1D 1，其中，以顶点A 为端点的三条棱长均为6，且它们彼此的夹角都是60°，下列说法中正确的是( )A ．AC 1＝6 6B ．AC 1⊥DBC ．向量B 1C →与AA 1→的夹角是60° D ．BD 1与AC 所成角的余弦值为63答案 AB解析 设AA 1→＝a ，AB →＝b ，AD →＝c ，则{a ，b ，c }是空间的一个基底．因为以顶点A 为端点的三条棱长均为6，且它们彼此的夹角都是60°，所以AA 1→·AB →＝AA 1→·AD →＝AD →·AB →＝a ·b ＝a ·c＝c ·b ＝6×6×cos 60°＝18，|AC 1→|2＝(AA 1→＋AB →＋AD →)2＝(a ＋b ＋c )2＝a 2＋b 2＋c 2＋2a ·b ＋2b ·c＋2a ·c ＝36＋36＋36＋3×2×18＝216，则|AC 1→|＝|a ＋b ＋c |＝66，A 正确.AC 1→·DB →＝(a ＋b ＋c )·(b －c )＝a ·b －a ·c ＋b 2－b ·c ＋c ·b －c 2＝0，B 正确．连接A 1D ，显然△AA 1D 为等边三角形，则∠AA 1D ＝60°.因为B 1C →＝A 1D →，且向量A 1D →与AA 1→的夹角是120°，所以B 1C →与AA 1→的夹角是120°，C 不正确．因为BD 1→＝c ＋a －b ，AC →＝b ＋c ，所以|BD 1→|＝（c ＋a －b ）2＝62，|AC →|＝（b ＋c ）2＝63，BD 1→·AC →＝(c ＋a －b )·(b ＋c )＝36，所以cos 〈BD 1→，AC →〉＝BD 1→·AC →|BD 1→||AC →|＝3662×63＝66，D 不正确．4.如图，在三棱柱ABC －A 1B 1C 1中，BC 1与B 1C 相交于点O ，∠A 1AB ＝∠A 1AC ＝60°，∠BAC ＝90°，A 1A ＝3，AB ＝AC ＝2，则线段AO 的长度为( )A.292 B.29 C.232 D.23 答案 A5．正四面体ABCD 中，M ，N 分别为棱BC ，AB 的中点，则异面直线DM 与CN 所成角的余弦值为________．答案 166.如图，在长方体ABCD －A 1B 1C 1D 1中，AB ＝1，BC ＝2，AA 1＝3，E 为CC 1上的点，且CE ＝1，求异面直线AB 1，BE 所成角的余弦值．解析 AB 1→·BE →＝(AB →＋BB 1→)·(BC →＋CE →) ＝AB →·BC →＋AB →·CE →＋BB 1→·BC →＋BB 1→·CE →＝0＋0＋0＋3＝3.依题意，易知|AB 1→|＝10，|BE →|＝5，所以cos 〈AB 1→，BE →〉＝AB 1→·BE →|AB 1→|·|BE →|＝310×5＝3210.即异面直线AB 1，BE 所成角的余弦值为3210.。

课时作业(五)Unit 2Section ⅡLearning AboutLanguage层级一课时跟踪检测维度1单句语法填空1．This time tomorrow, we ________ (sit) in the cinema and watching a film.2．I feel so excited! At that time tomorrow morning, I ________ (fly) to Shanghai.3．In the past three years, Liu Mei ________ (make) great progress in her study.4．Daniel's family ________ (enjoy) their holiday in Huangshan this time next week.5．I ________ (fly) from Miami to New York to meet the other members of the group at this time tomorrow.6．At 7 o'clock this evening we ________ (celebrate) Tom's birthday.7．The car ________ (go) at the present speed until it reaches the foot of the mountain at about nine o'clock tonight.8．Will you ________ (work)on your report this time tomorrow?9．I ________ (tell) him the news when he comes back.10．Look at the dark clouds over there. I think it ________ (rain) soon.11．She ________ (go) to the zoo to see the lovely bear next week.12．Next Friday I will go to another concert.They ________ (play) some music by Mozart at that time.维度2语法与写作1．下个星期的这时候，我们将在那个工厂劳动。

D．若细胞 4 是效应 T 细胞，则其与靶细胞是通过细胞膜直 接接触传递信息的
解析：细胞 1 是内分泌细胞，通过分泌激素与靶细胞进行 信息交流。细胞 2 和细胞 3 都是神经细胞，它们之间通过神经 递质进行信息传递，因此细胞 1 与靶细胞之间以及细胞 3 与细 胞 2 之间都是通过化学物质进行信息交流。化学物质通过与靶 细胞表面的受体蛋白结合将信息传递给靶细胞。效应 T 细胞与 靶细胞是通过细胞膜直接接触传递信息的。
____D__N_A________ 共 同 组 成 ， 前 者 进 入 细 胞 核 的 通 道 是 [_______2________]_____核__孔________。其在细胞内具有重要的功
能。在细胞生长、代谢旺盛但分化程度较低的细胞中，其数目 _____较__多________。
(3) 与 某 种 RNA 的 合 成 以 及 核 糖 体 形 成 有 关 的 结 构 是 [______4_________]______核__仁_______。
解析：细胞膜控制物质进出细胞的作用是相对的，一些对 细胞有害的物质也有可能进入细胞，A 项错误；细胞间的信息 交流有多种形式，不一定依赖于细胞膜上的受体，如高等植物 细胞之间可通过胞间连丝进行信息交流，B 项错误；一切细胞 均具有细胞膜，细胞膜的支架是磷脂双分子层，C 项正确；与 动物细胞相比，植物细胞放在清水中不会涨破主要是细胞壁起 着重要的作用，D 项错误。
A．说明细胞膜有信息传递功能 B．说明细胞膜具有一定的流动性 C．图中所示细胞膜的识别功能依赖于膜上的载体蛋白 D．说明细胞膜具有物质运输功能
解析：题图中所示细胞膜的识别功能是指神经递质与突触 后膜上的受体蛋白结合，而不是载体蛋白。突触小泡膜与突触 前膜融合将神经递质排到突触间隙，体现了细胞膜的流动性和 物质运输功能。

五年级下册英语课时作业第五单元全文共10篇示例，供读者参考篇1Title: My Adventures in English ClassHey guys, it's me, Tim! Today I want to tell you all about the fun we had in our fifth-grade English class. Our teacher, Miss Smith, is super cool and always makes learning English so much fun.In the fifth unit of our English textbook, we learned all about different foods and drinks. We learned how to talk about our favorite foods and how to order food in a restaurant. It was so cool because we got to practice speaking with each other and pretend we were in a real restaurant.Miss Smith also taught us about different types of food from around the world. We learned about sushi from Japan, pizza from Italy, and tacos from Mexico. It was so interesting to learn about how food is different in different countries.One of the most fun activities we did was a role-playing game where we had to pretend to be a chef and a customer. Iwas the chef and had to take orders from my classmates. It was so much fun trying to remember all the food vocabulary we had learned.Another fun activity we did was a food tasting party. Each of us had to bring in a dish from our culture or a dish we really liked. We got to try foods from China, India, Italy, and many other countries. It was so cool to taste new foods and learn about different cultures.I can't wait for our next English class adventure. Learning English is so much fun, and Miss Smith makes it even more exciting. I'm so grateful to have such an amazing teacher and classmates to learn with. English class rocks!篇2Hey guys, today I want to tell you about our fifth unit in the English class of the fifth grade. It's super fun and interesting, so let's get started!In this unit, we learned a lot of new words and phrases to help us describe our daily routines. We talked about what time we wake up, have breakfast, go to school, do our homework, and so much more. It was cool to learn all these new words because now we can talk about our daily lives in English.We also learned about different activities we can do in our free time. Like playing sports, watching TV, reading books, and hanging out with friends. It was fun to talk about our hobbies and interests and learn new words to describe them.Another cool thing we did in this unit was learn about different types of weather. We learned words like sunny, rainy, cloudy, and windy. It was interesting to talk about the weather in English and learn how to describe what it's like outside.Overall, I really enjoyed this unit in our English class. It was fun to learn new words, talk about our daily routines and hobbies, and learn how to describe the weather. I can't wait to keep learning more in our next unit!篇3Hello everyone! I am so excited to share with you all about what we have learned in the fifth unit of the 5th grade English textbook. This unit is all about different countries, cultures, and traditions. Let me tell you all about it!First, we learned about the United States. We learned that the U.S. is a big country with lots of different states. Each state has its own flag and flower. We also learned about famous American symbols like the Statue of Liberty and the bald eagle. Itwas so cool to learn about the different states and their special things!Next, we learned about Japan. Japan is a country in Asia with a rich history and culture. We learned about Japanese traditions like tea ceremonies, calligraphy, and origami. We even got to try making our own origami animals! It was so fun to learn about a different country and their unique customs.After that, we studied France. France is a beautiful country with famous sights like the Eiffel Tower and the Louvre Museum. We learned about French food like croissants and baguettes, and even got to taste some in class! We also learned a few French words and phrases, like "bonjour" and "merci." It was so cool to learn about a country on the other side of the world!Finally, we talked about Australia. Australia is a big island country with unique animals like kangaroos and koalas. We learned about Aboriginal art and culture, and even tried to paint our own Aboriginal-inspired artworks. It was so interesting to learn about the different cultures and traditions of Australia.Overall, this unit was so much fun and I learned a lot about different countries around the world. I can't wait to keep learning more in our next unit! Thank you for reading my article and Ihope you enjoyed learning about the fifth unit of our English textbook. Bye for now!篇4Hello everyone! Today I want to tell you all about our English homework from Unit 5 of the fifth grade textbook. This unit is all about different types of animals and the habitats they live in. It's super interesting, so let me tell you all about it!First, we learned about animals that live in the ocean. There are so many cool creatures like dolphins, sharks, and octopuses. We also learned about how important it is to protect the ocean and keep it clean for these animals.Next, we talked about animals that live in the desert. Did you know that camels can go without water for a really long time? It's so cool! We also learned about how these animals have adapted to survive in such a dry and hot environment.After that, we studied animals that live in the rainforest. There are so many colorful birds and adorable monkeys that call the rainforest home. It's important for us to protect the rainforest and all the animals that live there.Finally, we learned about animals that live in the Arctic. Polar bears and penguins are just a few of the incredible creatures that survive in the icy cold of the Arctic. We also discussed how climate change is affecting their habitats.I really enjoyed learning about all these different animals and their habitats. It's so important for us to take care of the Earth and all the creatures that live on it. I can't wait to learn more in our next unit!That's all for now. Remember to study hard and do your best on your homework. See you all in class!篇5Hello everyone! Today, I want to share with you what I have learned in the fifth unit of the English textbook in the fifth grade. This unit is so fun because we are learning a lot of new words and grammar rules.First, we learned about different types of weather. We learned how to describe the weather using words like sunny, cloudy, rainy, windy, and snowy. We also learned how to ask and answer questions about the weather. For example, "What's the weather like today?" "It's sunny and hot!"Next, we learned about different activities we can do in different weather conditions. For example, when it's sunny, we can go to the beach and swim. When it's rainy, we can stay indoors and watch movies. It's important to know what to do in different weather so that we can stay safe and have fun.We also learned about different seasons and the changes in weather that happen during each season. For example, in the spring, the weather starts to get warmer and flowers start to bloom. In the summer, it's hot and we can go swimming in the pool. In the fall, the weather gets cooler and the leaves change colors.Overall, I really enjoyed learning about weather and seasons in this unit. I can't wait to keep learning more English in the next unit! Thank you for reading my article. Goodbye!篇6Title: My Experience in English Class in Grade 5Hi everyone! My name is Lily and I am in the fifth grade. Today, I want to share with you all about my experience in English class in Grade 5, specifically in Unit 5.In Unit 5, we learned a lot of new and interesting things. We learned about different types of animals, the weather, and how to describe people. It was so much fun! My favorite part was learning about animals because I love animals so much. We learned about mammals, reptiles, birds, and insects. Did you know that a dolphin is a mammal, not a fish? I was so surprised when I found out!Another cool thing we learned about in Unit 5 was the weather. We learned about different types of weather like sunny, rainy, windy, and snowy. We even learned how to say the weather in different seasons. It was really helpful because now I can talk about the weather with my friends and family.Lastly, we learned how to describe people in English. We learned adjectives like tall, short, long hair, and curly hair. It was so much fun describing each other in class. I described my best friend as tall and kind. It was a great way to practice our English speaking skills.Overall, Unit 5 was a blast! I learned so much and had so much fun in English class. I can't wait to learn more in Grade 5. English class is the best! Bye for now!篇7Title: My Adventures in the Fifth Grade English ClassHi everyone! Today I want to share with you all about my adventures in the fifth grade English class. We are currently studying the fifth unit of our English textbook, and it has been so much fun!In this unit, we have been learning about different topics such as animals, jobs, hobbies, and places. We have been practicing our speaking, listening, reading, and writing skills through various activities and exercises.One of my favorite activities so far has been the role-playing games we have been doing in class. We get to pretend to be different animals, professions, or characters and have conversations with each other. It's been a great way to improve our speaking and listening skills while having fun at the same time.Another fun activity we did was creating our own comic strips using the vocabulary and grammar structures we have learned in this unit. We got to be creative and come up with our own stories featuring animals, jobs, or hobbies. It was a great way to practice our writing skills in a fun and engaging way.I also enjoyed the vocabulary games we played in class. We had competitions to see who could remember the most words related to the topics we have been studying. It was a great way to review the vocabulary and have a little friendly competition with my classmates.Overall, I have been having so much fun in the fifth grade English class. I have been learning a lot and improving my English skills in a fun and interactive way. I can't wait to see what other adventures await us in the next unit!篇8Oh wow, I can't believe it's already time for our fifth unit in the fifth grade English class! This unit is going to be so much fun, I just know it. We're going to learn all about different topics like animals, food, and hobbies. I'm so excited to dive into all of these new words and phrases.In this unit, we'll be learning how to talk about our favorite animals and describe them using adjectives. I can't wait to share with my classmates all about my pet cat, Fluffy. She's so cute and fluffy, just like her name suggests. I'm going to use words like playful, friendly, and cuddly to describe her.We'll also be practicing ordering food at a restaurant and talking about our favorite snacks. I love pizza, so I'll definitely be talking about that a lot. I'll ask my friends what their favorite foods are and see if we can come up with a list of the best snacks ever.And don't forget about hobbies! We'll be learning how to talk about the things we like to do in our free time. I can't wait to share with everyone how much I love drawing and playing soccer. Maybe I'll even find some new hobbies to try out.I know this unit is going to be amazing, and I can't wait to dive in and learn everything there is to know. English class is always so much fun, and I'm sure this unit will be no different. Let's get studying and make sure we know all of our vocabulary words and phrases like the back of our hand!篇9Hello everyone! Today I want to talk about our English homework from the fifth unit of the fifth grade textbook. This unit is all about different activities we can do in our free time.One of the activities we learned about is playing sports. I love playing soccer with my friends after school. It's so much fun to run around and score goals. I also like swimming in thesummer when it's hot outside. It's a great way to cool off and exercise at the same time.Another activity we talked about is reading books. I enjoy reading adventure stories and mysteries. It's like going on an adventure without leaving my bed! Reading is a great way to relax and learn new things.We also learned about playing musical instruments. I have been learning to play the piano for a while now, and it's so much fun. I love practicing my favorite songs and playing for my family.Overall, I think it's important to have hobbies and activities that we enjoy. It helps us relax, have fun, and learn new things. I can't wait to finish this unit and learn even more fun activities in English class!篇10Oh gosh, it's time for our fifth unit homework in the English class! This unit is so cool because we get to learn all about different countries and their cultures. Our teacher gave us a fun assignment to write an article about a country of our choice. I picked Japan because I love sushi and anime!Japan is a super cool country with lots of cool things to see and do. One of the most famous things in Japan is Mount Fuji, which is a huge volcano and the highest mountain in Japan. People from all over the world come to see Mount Fuji and take pictures of it. I wish I could go there someday!Another awesome thing about Japan is the food. Sushi is my favorite, but there are so many other yummy things to try like ramen, tempura, and mochi. I also heard that they have a lot of cool festivals like cherry blossom festivals and lantern festivals. I would love to see all the beautiful decorations and try all the delicious food!In Japan, people also celebrate a holiday called "Golden Week" where they have a whole week off to relax and spend time with their families. I think that sounds so fun! I wish we had a holiday like that in my country.I can't wait to finish my article and share it with my classmates. Learning about different countries is so interesting and I'm so grateful for the opportunity to learn about Japan. I hope one day I can visit Japan and experience all the amazing things I've learned about. Japan, I'll be seeing you soon!。