试题与答案

某同学用大头针、三角板、量角器等器材测半圆形玻璃砖的折射率.开始玻璃砖的位置如图

题型:填空题

题目:

某同学用大头针、三角板、量角器等器材测半圆形玻璃砖的折射率.开始玻璃砖的位置如图中实线所示,使大头针P1、P2与圆心O在同一直线上,该直线垂直于玻璃砖的直径边,然后使玻璃砖绕圆心O缓慢转动,同时在玻璃砖的直径边一侧观察P1、P2的像,且P2的像挡住P1的像.如此观察,当玻璃砖转到图中虚线位置时,上述现象恰好消失.此时只须测量出______,即可计算出玻璃砖的折射率.请用你的测量量表示出折射率n=______.

答案:

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参考答案:A, B, C, D, E

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题型:阅读理解

阅读理解。

    A wise man used to go to the ocean to do his writing. He had a habit of walking on the beach every

morning.

    One day, when he was walking along the shore(海岸), he saw a young man moving like adancer. He

smiled to himself at the thought that someone would dance on the beach. So he began to walk faster to

catch up.

    As he got closer, he saw that the young man wasn’t dancing, but instead he was reaching down to the

shore, picking up something and very gently throwing it into the ocean.

    He called out, "Good morning! What are you doing?" The young man stopped, looked up and replied,  "Throwing starfish in the ocean." "I guess I should have asked, why are you throwing starfish in the ocean?"

"The sun is up and the tide(潮汐)is going out. And if I don’t throw them in, they’ll die."

     "But, young man, don’t you realize that there are miles and miles of beach and starfish all along it. You

can't possibly make a difference!"

    The young man listened politely. Then he bent down, picked another starfish, and threw it into the sea,

and said, "It made a difference for that one."

    There is something very special in each and every one of us. We have all been gifted(赋予) with the

ability to make a difference.

    We must each find our starfish. And if we throw starfish wisely and well, the world will be better.

1. What was the wise man used to doing every morning?

A. Taking a walk on the shore.

B. Watching the young man dance.

C. Meeting up with the young man.

D. Helping the young man pick up starfish.

2. Why did the young man throw the starfish into the ocean?

A. To have fun.

B. To study starfish.

C. To feed some fish.

D. To save starfish.

3. What can we learn from the story?

A. Each of us should learn to protect starfish.

B. People living on the shore always try to save starfish.

C. Each of us has the ability to make an important effect on something.

D. People can come up with some good ideas when walking on the shore.

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