Be careful when you ________ the street.
A: are crossing
B: is crossing
C: crossing
D: is cross
A: are crossing
B: is crossing
C: crossing
D: is cross
举一反三
- Be careful when ______ the road. A: [A] crossing B: to cross C: cross
- ______be careful when crossing the street! A: Must B: Should C: Ought to D: Do
- You can never be _________ careful when crossing this busy road.
- While crossing the street, __________. A: the light might be green B: there are no policemen C: be careful D: it is necessary to be careful
- The only way ______ the river is by ferry. There isn’t a bridge for miles. A: cross B: crossing C: to cross D: to crossing