I guess we ‘ve already talked about this before but I’ll ask you again just _____.
| A．by nature | B．in return | C．in case | D．by chance |
---Where’s Mabel?
---She _____ ping pong behind the teaching building.
| A．is playing | B．was playing | C．played | D．had played |
Quite a few tall buildings _______ the last two years.
| A．have been put up | B．were put up | C．had put up | D．put up |
Man-made-satellites______ into space by many countries.
| A．was sent up | B．is sent up | C．have been sent up | D．has been sent up |
I _______ all the words on the black board. May I go home now?
copy B. will coup C. copied D. have copied
Nobody knew _______ a living in that country.
| A．to do | B．to make | C．how to do | D．how to make |