Look! The ground is wet. It must have rained last night, ________？
| A．hasn't it | B．hadn't it |
| C．mustn't it | D．didn't it |
When you get involved in sports, a lot of racial____are broken down because players developed friendship quickly.
| A．barriers | B．threats | C．approaches | D．hardships |
--- Jack fell off theladder yesterday，but he is all right now.
---What a lucky dog! He ________himself badly.
| A．should injure | B．might injure | C．should have injured | D．could have injured |
It was from only a few supplies that she had bought in the village _____the hostess cooked such a nice dinner.
| A．where | B．that | C．when | D．which |
Drinking water , having a healthy snack and taking exercise are all positive ways to ____you when you are working on a tight schedule.
| A．relieve | B．refresh | C．liberate | D．comfort |
We should consider the students’ request ______the school library provide more books on popular science.
| A．that | B．when | C．which | D．where |