The volunteers many signs to remind people to protect the environment.
| A．put on | B．put up | C．put down | D．put off |
useful robot! It can help with the housework like a human servant.
| A．How | B．What an | C．How a | D．What a |
It’s reported that there are more than 300 smokers in China, nearly a third of all the smokers in the world.
| A．million | B．millions |
| C．million of | D．millions of |
— May I watch TV now, mum?
— No, you . You must clean your room first.
| A．may not | B．needn’t | C．can’t | D．mustn’t |
Mary used to in the countryside, but now she is used to in the city.
| A．live ; live | B．live ; living |
| C．living ; live | D．living ; living |