问题
选择题
| 如图所示，甲、乙两束单色光同时射到两种介质的分界面MN上，由于发生折射而合为一束，如图所示（反射光未画出），则下列判断正确的是：（ ） A．甲光的频率比乙光的频率大 B．相同条件下，甲光比乙光容易发生衍射 C．对同种介质，甲光的折射率比乙光的折射率大 D．在同种介质中甲光光速比乙光光速小  |
答案
答案：B
搜题请搜索小程序“爱下问搜题”
| 如图所示，甲、乙两束单色光同时射到两种介质的分界面MN上，由于发生折射而合为一束，如图所示（反射光未画出），则下列判断正确的是：（ ） A．甲光的频率比乙光的频率大 B．相同条件下，甲光比乙光容易发生衍射 C．对同种介质，甲光的折射率比乙光的折射率大 D．在同种介质中甲光光速比乙光光速小 |
答案：B
| 从下列方框中选适当的词或短语填空，注意其形式变化。 | |
2. The boy worked hard in the summer vacation to make enough money to pay his ____. 3. Everybody is supposed to be ____ in all kinds of activities in the school. 4. He is willing to help others whenever they are ____. 5. Even if you fail the first time, never ____. Just keep on going. 6. After years of hard work, the young man succeeded in getting a doctor's____. 7. ____, I don't know the person who spoke to me just now. 8. If you have any problem, you'd better ____ your teacher for help. 9. He stole several cars and was caught and now he is ____. 10. The boy broke the window, but luckily he ____ the punishment. |