—Must I take my umbrella?
—No，you ___. It’s not going to rain.
| A．need |
| B．don’t have to |
| C．haven’t to |
| D．can’t |
The school has developed an online systemstudents can choose their own teachers.
| A．which | B．that | C．whom | D．where |
We’d better stay here a little longerhe turns up unexpectedly.
| A．although | B．in case | C．since | D．if only |
---I’m sorry, but there is no smoking on this flight.
---Oh, I _____that. Sorry, I won’t again.
| A．don’t know | B．didn’t know | C．won’t know | D．haven’t known |
---Have you read the book?
---Yes. But that one is _____worth reading. I suggest you______ it if you have time.
| A．best; read | B．well; read | C．better; read | D．more; should read |
_____the problem of land erosion getting more serious, the government is searching for a way to deal with it.
| A．As | B．With | C．When | D．If |