--- Had we been more careful, the accident might not have happened.
--- But we _____ at that time.
| A．hadn’t | B．didn’t | C．weren’t | D．might not |
23．What we want_____good textbooks.
| A．have | B．has | C．is | D．Are |
22．Half of the food in the bag_____bad．You’d better throw it away．
| A．has | B．have | C．are | D．Is |
21． More than one high official_____by the police since the mayor war shot dead.
| A．has been questioned | B．have been questioned |
| C．was questioned | D．were questioned |
20．She is the only one of the students who____a winner of the match．
A．1s B are C．have been D．had been
19.To play table tennis and to go swimming_____good for character training
A is B．are C was D were