It was in the school __________ he had studied ___________ he began the important experiment.
| A．that; where | B．in which; which |
| C．where; that | D．where; in which |
I _____ for five minutes； why don’t they come？
| A．am calling | B．called |
| C．was calling | D．have been calling |
It’s good that we _____ to the park because it’s started to rain.
| A．don’t go | B．hadn’t gone |
| C．didn’t go | D．wasn’t going |
. Look at that little boy wandering about — perhaps he _____ his mother.
| A．will lose | B．is losing |
| C．had lost | D．has lost |
“You’ve left the light on.” “Oh, so I have. _____ and turn it off.”
| A．I’ll go | B．I’ve gone |
| C．I go | D．I’m going |
The bridge, which _____ 1688, needs repairing.
| A．is dated from | B．was dated from |
| C．dates from | D．dated from |