There will be less pollution ___more people use public transportation .
| A．but | B．though | C．unless | D．if |
_____the time I got to the bus stop, the bus had already left.
| A．At | B．In | C．For | D．By |
---Don’t worry. Your brother is coming to help you.
---________ he doesn’t come?
| A．What about | B．Why not |
| C．What if | D．What for |
---Listen! Peter is singing in the classroom!
---It _____ be him. He has gone back to his hometown.
| A．must | B．mustn’t |
| C．may not | D．can’t |
---What are these bottles?
---Drinking water.
| A．used by | B．used to |
| C．used for | D．used up |
There was _____ woman in the room, sitting and looking at me in the dark.
| A．a 80-year-old | B．an 80-year-old |
| C．a 80-years-old | D．an 80-years-old |