It is pretty well understood controls the flow of carbon dioxide in and out the atmosphere today.
| A．that |
| B．when |
| C．what |
| D．how |
The meeting ________ tomorrow is very important．
| A．held | B．to hold | C．to take place | D．taken place |
Although this ______ sound like a simple task, great care is needed．
| A．must | B．may | C．should | D．shall |
---- The fish soup is delicious．I’d like some more．
---- Sorry．There is ________ left．
| A．none | B．neither | C．no one | D．a little |
---- My key is gone．Have you seen it anywhere?
---- Oh, it is in the room ______ we had a talk last night．
| A．that | B．which | C．where | D．what |
With housing prices ______ sharply, many people have no idea whether they should buy an apartment or not．
| A．risen | B．arising | C．raising | D．rising |