要想使反射光线与入射光线的夹角是140°，入射角大小应是（）_爱下问搜题

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问题选择题

要想使反射光线与入射光线的夹角是140°，入射角大小应是（　　）

A．40°

B．50°

C．70°

D．140°

答案

因为入射光线和反射光线的夹角是入射角和反射角之和，又因为反射角等于入射角，所以入射角的大小为：

1

2

×140°=70°．

故选C

完形填空

One of my favourite films is Mr. Bean At a Fancy（化装）Restaurant. In the film, after being 21 at his table，Mr. Bean takes out a 22 ，writes a few words on it，signs his name，puts it into an envelope and 23 it on the table．After a moment，he looks at the 24 but this time he looks surprised，as if he did not know it was there．He opens it to find a birthday card and delightedly puts it on the table for everyone to see．
When he looks at the 25 ，an astonished look quickly 26 on his face．He takes all 27 out of his pockets，counts it and puts it in a saucer（碟子）．He then looks from the menu to the money with 28 until he finds one thing that makes him smile. He 29 a dish called “steak tartare.” When the dish arrives，he is 30 to discover that “steak tartare” is 31 a raw（生肉的）hamburger．He 32 an attempt to eat it，but it is 33 ，from the look on his face，that he finds the taste really terrible．He cannot 34 his feelings，except when the waiter asks whether everything is OK．He smiles and nods， 35 that everything is fine．36 no one is looking，however，he 37 himself hiding the raw meat anywhere he can 38 ，inside a sugar bottle，a tiny flower vase and under a plate．He becomes so disappointed in the end that he 39 hides some inside the 40 of a woman sitting near him and throws some under the seat of the restaurant’s violinist！
I like to watch Mr. Bean on TV but I wouldn’t want to meet someone like him in real life．

C．surroundings

A．satisfaction

B．recognizing

单项选择题

有关资金时间价值的说法，不正确的是( )。

A．资金的价值是随时间变化的，是时间的函数，随时间的推移而增值

B．任何积压资金或闲置资金不用，就不存在资金的时间价值

C．在工程经济分析时，不仅要着眼于方案资金量的大小，也要考虑资金的时间价值

D．投资经营的一项基本原则就是充分利用资金的时间价值并最大限度地获得其时间价值