问题 问答题

如图所示,一束光从空气斜射向水面,入射光线及法线已经画出.请画出这条入射光线的反射光线和折射光线(注意角度特点并标出箭头方向)

答案

(1)过入射光线和水面的交点作一条垂直于水面的法线,根据反射角等于入射角,在法线的另一侧,可作出反射光线,并且标出反射光线的方向;

(2)根据光的折射定律,因为光线是从空气进入水里,是从密度小的介质进入密度大的介质,折射角应该小于入射角,在法线的另一侧,作出折射光线并且标出折射光线的方向.

(3)如图所示.

完形填空
根据对话内容,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。
Telling the truth is a good habit.     小题1:    Here is a story of a man who did a lot of bad things, but his promise to tell the truth saved him.
Once a man came to the prophet(预言家) Muhammad and said,“ I have many bad habits.     小题2:   ” The prophet said, “Give up telling lies first and always speak the truth.” The man promised to do so and went home.
   小题3:   Before setting out, he thought for a moment about the promise he made with the prophet. “If tomorrow the prophet asks me where I have been, what shall I say? If I tell the truth, I would be punished for stealing.” So the man decided not to steal that night, and gave up this bad habit.
The next day, he felt like drinking wine.     小题4:   He said to himself, “I cannot tell the prophet that I drank some wine. And if I speak the truth, people will hate me, because a Muslim is not allowed to drink wine.” So he gave up the idea of drinking wine.
In this way, whenever the man thought of doing something bad, he remembered his promise to tell the truth at all time.     小题5:   So if you always speak the truth, you can be a good person.
A. You will make more friends in this way.
B. One by one, he gave up all his bad habits.
C. Which one of them should I give up first?
D. At night he was about to go out to steal.
E. Is there any good way to give up my bad habits?
F. When he was about to do so, he thought of his promise again.
G. If you always speak the truth, you can save yourself from a lot of trouble!
问答题