As we all know．____life is hard for any of us. If we live___ happy life，we must all work harder.
| A．／：／ | B．／；a | C．a；／ | D．a；a |
As soon as the children _____ themselves in their seats in the classroom, the bell rang.
| A．sat | B．settled | C．took | D．put |
It was not until Bob took off his dark glasses that I _____ him.
| A．realized | B．requested | C．recorded | D．recognized |
Buses here are always crowded with passengers, so I prefer _____ there rather than take a bus.
| A．cycle | B．cycling | C．to cycle | D．being cycled |
------- Where did you find him?
-------It was in the hotel _____ he lived.
| A．that | B．where | C．which | D．what |
The scientist ______ much of his time to increasing the rice production.
| A．spent | B．offered | C．devoted | D．paid |