When asked why he went there, he said he was sent there ____ for a space flight.
| A．training | B．being trained | C．to have trained | D．to be trained |
Mr. Duncan raised an unnecessary question __________ he then failed to find an answer.
| A．to which | B．for which | C．with which | D．by which |
—What do you think of his speech at the court?
—Er..., sorry, I ________ about something else.
| A．had thought | B．thought |
| C．was thinking | D．have been thinking |
We still remember once _________ round the famous tower when we were young.
| A．having taken | B．to be taken |
| C．having been taken | D．to have taken |
----Marx looks nervous.
----So __________ you if you had so fierce a competition.
| A．do | B．did | C．will | D．would |
_________ caused the accident is still a mystery.
| A．How | B．What | C．That | D．Where |