Did you call to book a ticket for the concert ?—Not yet, but I _______ .

Was it in 1969 ____ the American astronaut succeeded ____ landing on the moon?

____ a basketball player ，he wants to be a person ____ Yao Ming is popular.

The new laboratories will be constructed this year, and local firms have been asked to ________ the work. [ ]

Hospital staff burst into cheers after doctors completed a 20hour operation to have _________ one-year-old twins at the head.