John talked with me for about an hour yesterday．Never ________ him talk so much．
| A．did I hear | B．had I heard | C．I had heard | D．I heard |
Not until I began to work ____ how much time I had wasted.
| A．didn't I realize | B．did I realize | C．I didn't realize | D．I realized |
I want to be left alone ___ things out.
| A．think | B．thought | C．thinking | D．to think |
Before __ the trunk must be checked.
| A．used | B．to use | C．being used | D．to be used |
The young Swede was made ___ a lot of practice before the Napoleon’s inspection.
| A．have | B．had | C．having | D．to have |
Everybody knows that we should not drink ___ water, or they will get burnt.
| A．boil | B．boiled | C．boiling | D．being boiled |