___________ should not be allowed to go out at night.
| A．Twelve-years -old | B．Twelve-year-olds |
| C．Twelve years old | D．Twelve year olds |
The robot needs _______ once a month. And we will check it for you for free.
| A．to check | B．checked |
| C．checking | D．to checking |
We didn’t know how to find them because they didn’t tell us _______.
| A．which room did they live |
| B．which room they lived in |
| C．which room they lived |
| D．which room did they live in |
In order _______ his English，he joined an English club.
| A．improving | B．to improve |
| C．improves | D．improve |
Don’t make the students _______ this or that . They are busy.
| A．to do | B．do |
| C．doing | D．done |
---It’s said that scientists are working hard to ________ a way to deal with H7N9 avian influenza(H7N9禽流感)
---Really? That’s great!
| A．caught up with | B．come up with |
| C．agreed with | D．compared with |