问题 问答题 简答题

为何在设计望远镜系统时要将孔径光阑置于物镜上?

答案

参考答案:

望远镜是目视系统,需要与人眼联用。根据光瞳衔接的原则,望远镜的出瞳应与人眼的瞳孔衔接,故它因该位于望远目镜之后,一般要求6mm以上的距离。计算表明,将孔径光阑置于物镜上可以满足对出瞳的位置要求,而且望远镜的物镜、棱镜的尺寸最小

阅读理解

Peter was getting ready to graduate from the college. He loved a beautiful sports car for many months, and knew his father could well afford it for him. He told his father all that he wanted.

As the graduation day was coming near, Peter had got nothing from his father. On the morning of his graduation, his father called him into his study. He told his son how proud he was to have such a good son, and told how much he loved him. Then he gave his son a beautiful gift box. He opened the box, finding a lovely book, a Bible(圣经), with the young man’s name in it. Angrily he raised his voice to his father and said, “With all your money you give me a Bible?” He then ran out of the house, leaving the Bible.

Many years later, Peter was very successful in business. He had a beautiful house and a wonderful family. Realizing his father was old, he thought he should go to see him. He had not seen him since that graduation day. Unfortunately, he was told that his father had died.

When he reached his father’s house, he began to take care of his father’s papers. And then he found the Bible, just as he had left it years ago. With tears, he opened it and began to turn the pages. As he was reading, from the back of the Bible dropped a car key. That was the key to the sports car he wanted so much. Sudden sadness and regret (悔恨)filled his heart.

Sometimes we don’t realize the good luck that we already have because we don’t know the gift box is packed in a different way. The gift box may be the door to happiness. It is just waiting for us to open.

小题1:The son would like his father to buy him___________.

A.a beautiful house

B.a Bible

C.a beautiful box

D.a sports car小题2:The son ran out of the house angrily because ____________.

A.his father said something wrong to him

B.his father gave him nothing

C.he thought his father only gave him a Bible

D.his father didn’t love him小题3:Many years later, the son_____________.

A.was told his father was still healthy

B.became a successful man

C.had a hard life

D.went to see his father quite often小题4:How did the son feel when he got the car key?

A.Excited and happy.

B.Worried and sad.

C.Disappointed and upset.

D.Sad and regretful.小题5:From the story, the writer wants to tell us ___________.

A.we may miss good luck because they are not packed as we expect

B.we should look after our parents carefully

C.our parents will give us everything we ask for

D.we should accept any gift that our parents give us

单项选择题