My father wanted to_________an LED light in my bedroom.
| A．put off | B．put up |
| C．put in | D．put on |
We can’t do two things _____.
| A．all the time | B．on time | C．at times | D．at a time |
Jim’s shirt is made _____ silk , and it’s made ______ china.
| A．in, of | B．from, of | C．of , in | D．from , in |
No smoking, please. It’s ____ the rules.
| A．against | B．for | C．on | D．at |
Although we are young, ______ we can still do something to help them.
| A．but | B．/ | C．and | D．however |
It is necessary _____ something to protect our environment.
| A．do | B．to do | C．does | D．doing |