问题 计算题

向月球发射的无线电波到达月球并返回地面,共需2.56s,无线电波的传播速度是3×108m/s,求月球与地面的距离是多少?

答案

解:无线电波从月球传到地面的时间为t=×2.56s=1.28s,

那么月球与地面的距离为S=vt=3×108m/s×1.28s=3.84×108m

阅读理解

根据下面短文的内容判断下列句子的正误,正确的用“A”表示,错误 的用“B”表示。

     On my first day of high school, I saw a boy from my class walking back home after school.

His name was David. He was carrying his books. As I was walking, I saw a group of kids running

towards him, knocking all his books out of his arms. And then they ran away. David fell down

and his glasses went flying. He looked up and I saw sadness in his eyes. I helped him to look for

his glasses and said, "The kids with bad manners should be punished. " There was a big smile that

showed real gratitude (感激) on his face.

     From then on we became friends. The more I got to know David,the more I liked him. Over

the next four years, we always studied,  played together and had a happy time.

     On the graduation (毕业) day, I could see that he was nervous about his speech. So I said,

"Hey, you will be the best!" Then he began, "Graduation is a time to thank those who helped you

succeed through those difficult years. Our parents, our teachers, but mostly our friends. Being a

friend to someone is the best gift you can give them. I'll tell you a story ..." I just looked at the

handsome popular boy in amazement as he told the story of the first day we met.

     Everyone was surprised to hear all about his hardest moment. I saw his mom and dad looking

at me and smiling that same thankful smile. Not until that moment did I realize its deep meaning.

Never underestimate (低估) the power of your actions. With one small action, you can change

a person's life. As you can see, "Friends are angels (天使) to make us rise when our wings (翅膀)

have problems flying. "

(      )1. The writer and David were classmates.

(      )2. The kids with bad manners were punished by the writer when they knocked David down.

(      )3. Everyone was surprised to hear all about David's hardest moment.

(      )4. The writer realized that one small action could change a person's life before hearing David's

            speech.

(      )5. The underlined sentence at the end of the passage means "A friend in need is a friend indeed

            (真正地)."

单项选择题