Don't touch the instruments in the laboratory ________ the teacher allows you to do that.
A．unless B．when
C．though D．because
The ________ you work， the more trust and praise you will get from your workmates.
A．more careful B．more carefully
C．most carefully D．most careful
—What beautiful flowers! I can’t decide ________ for my mom.
—For Mother’s Day， it can’t be better to buy some carnations.
A．when to choose B．which to choose
C．how to choose D．to choose what
—______ I see your ID card， sir?
—No problem. Here you are．
A．Can B．May
C．Need D．Must
If we cannot reach an ________ on the program， we will have to vote.
A．agreement B．development
C．treatment D．improvement
— When ________ you ________， Nancy?
— I’m not sure. There is a lot of traffic on the road today.
A．have； arrived B．did， arrive
C．do， arrive D．will， arrive
