完成句子。
1. It's not just because they ____（不能理解它是什么意思）.
2. F 2 F ____ （表示面对面）.
3. Homophone often use letters and numbers that ____（听起来像单词或单词的一部分）.
4. I don't think twelve-year-olds should be allowed to ____ （穿耳洞）.
5. I think teenagers should be allowed to____（与朋友们外出）.
6. If we can't wear our own clothes, we should be allowed to____ （设计自己的校服）.
7. I get nervous before big parties and then I ____（出皮疹）.
8. It isn't good to borrow your friends' books ____ （未经允许）.
 9. My life ____（有了很大的改变）in the last few years.

在△ABC和△A′B′C′中，如果AB=9，BC=8，AC=5，A′B′=$\frac{9}{2}$ , B′C′=$\frac{5}{2}$，A′C′=4，那么 （    ）

医生用膝跳反射诊断被测者神经系统是否受损．如图为该反射示意图，请回答：

生物进化的总体趋势，是由简单到复杂、由____到____、由水生到陆生．