超声波从一种介质进入另一介质后，其声束轴线与界面法线所成的夹角称为（）
A、入射角
B、折射角
C、扩散角
D、反射角
参考答案：B
用所给单词的正确形式填空。
1. There are many _____ in the river, and I can go _____ there. (fish)
2. The machine _____ (not work).There must _____ something wrong with it. (be)
3. —Does she like _____ a rope?
—No, she doesn't. She can't _____ a rope. (climb)
4. My sister does some _____ every morning. So she can _____ fast. (run)
5. My brother is good at _____, he can _____ in the river. (swim)
受到性骚扰的妇女可以向（）投诉。
A、公安机关
B、妇女联合会
C、所在单位
D、以上都是
