Professor Smith, along with his assistant, ________on the project day and night to meet the deadline.
| A．work | B．working | C．is working | D．are working |
The building is ___.
| A．twenty-metre-high | B．twenty metre high | C．twenty-metres-high | D．twenty metres high |
He ___ go to work by bus, but now he ___ riding a bicycle to work.
| A．used to; used to | B．used to; is used to | C．is used to; used to | D．is used to; is used to |
I don’t feel like ___ now.I’d prefer ___ my homework at present.
| A．to sleep ; doing | B．to sleep; to do | C．sleeping; doing | D．sleeping; to do |
---What ____ the population of China ?
---China has a population of 1.3 ____.
| A．is, billions | B．are; billions | C．is; billion | D．are; billion |
---I’m tired.Shall we find a chair ___ in the park? ----Good idea!
| A．to sit | B．to sit on | C．sitting | D．sit on |