1.adventure vt. 大胆进行；拿……冒风险 n. 冒险行动，冒险
adventure 所指的冒险一般只是刺激性强，并无多大危险，用作复数时，意为“冒险故事”。
venture 多指冒生命危险或重大的经济风险。
（1）An Antarctic expedition was once an adventure.
2.desert n. 沙漠 v. 离弃；抛弃；背弃；遗弃不顾 adj. 荒凉的；无人居
住的
(1)Many people deserted their houses for another place during the food
shortage.
(2)Travelling alone in the desert is very dangerous.
(3)The old man has lived on the desert island for 30 years.
3.dream vi. 做梦，梦见，常与of 或about 连用
vt. 做梦，梦见，常跟同源宾语
n. 梦；梦想
have dreams of doing sth.
4.take off 起飞；脱掉；突然上升；大受欢迎
（1）Sales of home cars have taken off in recent years.
5.major adj. 较大的；主要的；严重的 vi. 主修，专修（大学的某一科目）
n.少校；成年人；大学主修科目；主修专业
major in (美国口语)攻读，专修，主修
majority n. (pl. majorities)大部分，多数；
minority n. 少数
in the/ a majority 占大多数
a/the majority of 大多数的，大半的
6.experience n.(U)经验；（C）经历，阅历
vt. 经历，体验
experienced adj. 有经验的；熟练的
7.extra adv. 特别地；非常 adj.特别的；额外的
extraordinary adj. 非常的；离奇的；使人惊奇的
8.option n. (U)选择；选择权（C）（供）选择的事物
at one’s option 随意
have no option but to do sth. 不得不做某事
9.imagine vt. 想象，设想
imagine + n./that/wh- 想象……
doing sth.
sb. doing sth.
sb./sth. to be +n./adj.想象某人/某物是……
imagination n. 想象力，想象出来的东西，幻想
imaginative adj. 有想象力的，幻想的
imaginable adj. 可想象的；想象得到的
imaginary adj. 想象中的
10.luggage baggage (U)n. 行李
a piece of …
11.cost vt. 价值，花（多少钱）；丧失，牺牲 n. 价格；成本，费用；代价at a cost of 以……为代价
at all cost/costs 不惜任何代价
at any cost 无论如何
at half cost 以半价
at the cost of ……以……为代价
12.right now = just now 此刻，目前
right now = just now 刚才，一会儿以前
right now = directly,immediately,very soon 立刻，很快地
right away = at once = in no time 立即，马上
13.differ v. (1) differ from 不同，不一样，有区别，不像
(2) differ from/with sb. on/about sth. 不同意，持异议
differ in …..在……方面不同
different adj. 不同的
be different from …与……不同
difference n. 不同，差异
make a difference 起作用；有所成就
make no difference 没有影响
14.be anxious about/for …为…..而担心，渴望……
be anxious to do sth. 渴望做某事
速效基础演练
一．用括号内所给单词的适当形式填空。
1.The Chinese do not lack an adventurous (adventure) spirit.
2.This hotel has accommodation (accommodate) for 500 guests.
3.Housework is really tiring (tire) but I have to manage it every
day.
4.We waited for news with a growing sense of anxiety (anxious).
5.They have established a student organisation (organize).
6.He once was a famous BBC sports presneter (present).
7.The shy boy felt rather uncomfortable (comfortable) with
strangers.
8.Although our looks differ (different), we are both
attractive.
9.Is that optional (option)course as hard as everyone says?
10.The majority (major) of people seem to prefer TV to radio. 二．单项填空。从A,B,C,D和D四个选项中，选出可以填入空白处的最佳选项。
1. I can’t imagine such a poor man.
A. she marries with
B. she will marry with
C. her to marry
D. her marrying
2. The visiting professor giving lecture to students invited to meeting at a time.
A preferred; to being B. preferred; rather than C. preferred; than being D. preferred; to be
3. She waited in for her mother’s letter.
A. anxious
B. anxiety
C. anxiously
D. antique
4. In order to keep healthy, you should try to avoid foods that a lot
of fat.
A. include
B. contain
C. involve
D. deny
5. Our country has great changes in the past 30 years, which are the result of reform ans opening-up.
A. appeared
B. happened
C. taken place
D. experienced
6. This is . You may do it or not.
A. applicable
B. elastic
C. elementary
D. optional
7. You need a break. Why not take a week from work?
A. off
B. away
C. up
D. along
8. We all had some of the cake; I probably ate the .
A. majority
B. most
C. minor
D. major
9. I hesitate to get involved in this .
A. advantage
B. adventure
C. advance
D. advice
10. My parents spend too much money clothes. That is to say, clothes them a lot of money.
A. in; cost
B. buying; cost
C. on; costs
D. at; takes
11. They are busy for the meeting to be held tomorrow.
A. making arrangement
B. to make arrangement
C. making arrangement
D.
to make arrangements
12. The little boy dreams a pilot.
A. of becoming
B. to become
C. becoming
D. to becoming
13. The accident happened when his writing career really .
A. took off
B. took up
C. took down
D. took in
14. In order to show his boss what a careful worker he was, he took trouble over the figure.
A. extensive
B. spare
C. extra
D. supreme
15. These oranges taste .
A. good
B. well
C. to be good
D. to be well
16. The new tourist hotel will have for more than one thousand people.
A. convenience
B. accommodations
C. capability
D. capacities
三．完成句子。根据汉语提示，用所给的英语单词完成句子。
1. I feel uncomfortable when I stay in my friend’s home. (feel)
当我待在朋友家里时，我感觉不自在。
2. Most travelers were not satisfied with the accommodations arranged by the travel agent. (satisfied)
大多数旅游者对由旅游社安排的住宿和伙食不满。
3. The students are preparing for the coming final examination. (prepare)
学生们正在为即将到来的期末考试做准备。
4. Many people in foreign countries enjoy going on a hiking trip . (hike)
很多外国人喜欢进行徒步旅行。
5.What he said sounds reasonable, but it hasn’t practical uses. (sound)
他所说的听起来有道理，但它没有实际用途。第15章弹簧
元件
15.1 弹簧元件的的功用和类型
弹簧受外力作用后能产生较大的弹性变形，在机械设备中广泛应用弹簧作为弹性元件。
弹簧的主要功用有：1）控制机构的运动或零件的位置，如凸轮机构、离合器、阀门以及各
种调速器中的弹簧；2）缓冲及吸振，如车辆弹簧和各种缓冲器中的弹簧；3）储存能量，如
钟表、仪器中的弹簧；4）测量力的大小，如弹簧秤中的弹簧。
弹簧的种类很多，从外形看，有螺旋弹簧、环形弹簧、碟形弹簧、平面涡卷弹簧和板
弹簧等。
螺旋弹簧是用金属丝（条）按螺旋线卷饶而成，由于制造简便，所以应用最广。按其
形状可分为：圆柱形（下图a、b、d）、截锥形（下图c）等。按受载情况又可分为拉伸弹簧
（下图a）、压缩弹簧（下图b、c）和扭转弹簧（下图d）。
环形弹簧（下图a）和碟形弹簧（下图b）都是压缩弹簧，在工作过程中，一部分能量消耗在各圈之间的摩擦上，因此具有很高的缓冲吸振能力，多用于重型机械的缓冲装置。
平面涡卷弹簧或称盘簧（下图c），它的轴向尺寸很小，常用作仪器和钟表的储能装置。
板弹簧（下图d）是由许多长度不同的钢板叠合而成，主要用作各种车辆的减振装置。
本章主要介绍圆柱螺旋拉伸、压缩弹簧的结构和设计。
15.2 圆柱螺旋拉伸、压缩弹簧的应力与变形
一、弹簧的应力
圆柱螺旋拉伸及压缩弹簧的外载荷（轴向力）均沿弹簧的轴线作用，它们的应力和变形计算是相同的。现以圆柱螺旋压缩弹簧为例进行分析。
下左图所示为一圆柱螺旋压缩弹簧，轴向力F作用在弹簧的轴线上，弹簧丝是圆截面的，直径为d，弹簧中径为D2，螺旋升角为a。