5.编写程序求S=1+2+3+4+…+n的和(n由键盘输入),程序如下.在如下程序的横线上应填________.　　　　　　　　　　

4．一个四边形的四个内角成等差数列，最小角为，则最大角为________.　

3．函数在=1处的导数等于_________.　　　　

2．已知向量，若与共线，则等于______.　 　　 　　　

1．设全集U = R ，A =，则=_________.

80. We are interested in the weather because it _____ us so directly ------ what we wear, what we do, and even how we feel.

　 A. benefits　　 B. guides　　 C. affects　　 D. effects

　C. affects.

　 affect (=have an influence or effect on) 影响：The climate affected his health. (气候影响[损害]了他的健康。)

[注意]affect vt. 影响。effect n. (=influent) 影响, 作用：Some films have a misleading effect on children. effect vt. (=bring about) 实行, 进行, 产生......后果:1) I will effect my purpose: no-one shall stop me! 2) We hope to effect an improvement. (我们希望能引起改进。)

注意两个常用的习语:1) to that effect 那个意思的 (话) ：She said she hated spinach, or words to that effect. (她说她不喜欢吃菠菜或那个意思的话。) 2) to the effect that... 意思时说, 表示下述意思：I said a few words the effect that all he had told us was already well known. (我说了几句话, 意思是说他告诉我们的一切都已众所周知。

79. An early typewriter produced letters quickly and neatly; the typist, _____ couldn't see his work on his machine.

　 A. however　　 B. therefore　　 C. yet　　 D. although

　A. however.　

　　 however 然而。

本题译文：早期的打字机打起字来又快又整齐, 然而打字员不能看着机器键盘打字。

78. The reason why he adapted to the new situations quickly is that he has a _____ attitude.

　 A. changeable　　 B. alternate　　 C. movable　　 D. flexible

　D. flexible.

　　 flexible 灵活的, 可变通的; We need a foreign policy that is more flexible.

77. Motorists _____ of speeding may be banned from driving for a year.

　 A. convicted　　 B. arrested　　 C. charged　　 D. judged

　A. convicted.

be convicted to 被判有...... (罪) ：He was convicted of murder. (他被法院判有谋杀罪。)

76. He was not _____ to the club because he wasn't a member.

　 A. allowed　　 B. admitted　　 C. permitted　　 D. approved

　B. admitted.

　admit sb. to (=allow sb. or sth. to enter; let in) 允许某人某物进入; 让......进入：1) Children are not admitted. (儿童免进。) Only one hundred boys are admitted to the school the school every year. (这所学校每年只收100名男生。) admit (=acknowledge; confess) 承认, 供认：1) We have to admit that he is a highly competent man. (我们不得不承认他是一位能力很强的人。) 2) The thief admitted his crime. 3) She admitted having read the letter, 4) I admit breaking the window. 注意admit后可接动名词的一般式或完成式。5) We must admit the task to be difficult。注意admit也可以接复合结构。allow和permit后均可接sb. to do sth., 故不合本题题意。approve sth. 批准; approve of doing sth. (=think well of) 赞成, 赞许：1) I am afraid they won't approve of your going there. (恐怕他们不会赞成你去那里的。) 2) I don't approve of your way of looking at things. (我不赞同你看待事情的方法。)