Let’s go _____ the road now.—Wait a moment please. The light is red now.[ ]
Scientists say it may be five or six years_______it is possible to test this medicine on human patients.
The guests were _________ in the front rows ________ to the president attentively.
Don’t put the bike_______the teaching building.——Sorry, I won’t.
Whygo fishing with us at East Lake,Mile?