I was on the highway when this car went past fol. Lowed by a police car. They ______ at least 150 kilometers an hour.
| A．should have been doing | B．must have been doing |
| C．could have done | D．would have done |
It is reported that two schools，_______ are being built in my hometown，will open next year.
| A．they both | B．which both | C．both of them | D．both of which |
Some pre-school children go to a day care center, __________ they learn simple games and songs.
| A．then | B．there | C．while | D．where |
He was educated at the local high school, ______ he went on to Beijing University.
| A．after which | B．after that | C．in which | D．in that |
The road conditions there turned out to be very good, ____ was more than we could expect.
| A．it | B．what | C．which | D．that |
All the neighbors admire this family, ____ the parents are treating their child like a friend.
| A．why | B．where | C．which | D．that |