—Why ! Where's my passport? Maybe I left it on the plane.
--My Goodness ! You ____________ things behind.
A. had never left B. didn't leave
C. never left
When I came back from shopping, I found my purse __________.
| A．having stolen | B．being stolen | C．stolen | D．stealing |
Mr. Smith, may I have a word with you? I’ll try not to __________ too much of your time．
| A．take up | B．take on | C．take in | D．take off |
You may catch up with others __________ you work a little harder.
| A．so long as | B．so far as | C．however | D．unless |
Without electricity human life __________ quite different today.
| A．is | B．will be | C．would have been | D．would be |
Gunpowder is generally believed __________ in ancient China.
| A．to have invented | B．being invented | C．to have been invented | D．having invented |