Experiments of this kind ___in both the U．S and Europe well before the Second World War．
| A．had conducted | B．have conducted |
| C．have been conducted | D． had been conducted |
Now that we've discussed our problem, are people happy with the decisions ________？
| A．taking | B．take | C．taken | D．to take |
Sarah pretended to be cheerful，________nothing about the argument.(2011·全国Ⅱ)
| A．says | B．said | C．to say | D．saying |
He had no sooner finished his speech ________ the students started cheering.(2011·辽宁)
| A．since | B．as | C．when | D．than |
—It's nice.Never before________ such a special drink!
—I'm glad you like it.(2011·福建)
| A．I have had | B．I had |
| C．have I had | D．had I |
Was it on a lonely island ________ he was saved one month after the boat went down？(2011·四川)
| A．where | B．that | C．which | D．what |