问题 探究题

小林在探究光的折射规律时发现:当光由空气沿半圆玻璃砖边缘垂直射入圆心处发生反射和折射时,不断加大入射角会发生折射光消失而反射光却变得更亮的情况,如图所示,老师告诉他这是光的全反射现象。课后,小林查到光从玻璃射向空气时的一些数据如下表:

表中数据说明:

(1)光从玻璃斜射向空气时,折射角、反射能量随着入射角的增大而________ ,当入射角达到______°时,反射能量达到100%,就发生了全反射现象。

(2)根据光路可逆原理,当光从空气斜射向玻璃时,折射角________ 入射角(填“大于”、“等于”或“小于”)。

答案

(1)增大(或增加);41.8

(2)小于

完形填空

第二节(共5小题;每小题2分,满分10分)

  根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

  BEUING(Associated Press)- China has a growing middle class,a tradition of expecting education and 21 million new babies every year. 71

  While China may be the world's biggest toy maker,many of the best are exported. 72 It is said that the demand for educational toys is low.

  A US company,BabyCare,is trying to change that with a new way to sell toys in China. 73 People who join the company's "mother club" can get lectures and newsletters on baby and child devlopment at no extra cost,if they agree to spend 18 dollars a moth on the company's educational toys and child carebooks.

  "We want to build a seven year relationship with those people," said Matthew J.Estes,BabyCare's president." 74 " BabyCare works on a one - to - one advise parents,explain toys that are designed for children at each stage(阶段) of development to age six.

  BabyCare opened its first store in China last June in a shopping center in central Beijing and another near Beijing Zoo. 75

  It is a new model for China and develops a market in young children's education and health that no other companies are in.

A.It starts during pregnancy(孕期),when the anxiety and needs are highest.

B.The highest quality toys can be seen in the department stores all over China.

C.Selling educational toys should be easy.

D.It plans to have 80 stores in China within six years.  E.Department stores here do not have enough high quality toys.

  F.It will have more stores in the United States and some other countries.

  G.BabyCare works basically together with doctors in Beijing hospitals.

问答题 简答题