小题1: One of the rules is that all the students must pay a___________ to their teachers in class.

小题2:Fall is another way of saying a______________.

小题3: My mother p_______ coffee to tea. But I like tea a lot.

小题4:I won’t go to his birthday party u________ I am invited.

小题5:The old man lives alone and aren’t happy these days. Let’s go to see him and c________ him up.

小题6: There will also be exciting things waiting for you a____________ with difficulties.

小题7:It’s dishonest to try to c___________ one’s mistake with lies.

小题8: I want to take care of my health, so I m_____________ eat fruit and vegetables.

小题9:–W________ backpack is it?

– I don’t know. Let’s ask them and find the owner.

小题10: My watch is broken. I’ll get it m__________ this weekend.

完成下面问题：

（1）分离沸点不同但又互溶的液体混合物，常用什么方法？

（2）在分液漏斗中用一种有机溶剂提取水溶液里的某物质时，静置分层后，如果不知道哪一层液体是“水层”，试设计一种简便的判断方法。