Something has to be done to stop our rivers from being polluted,________?
A.doesn't it B.hasn't it C.does it D.haven't they
It is interest to observe_________common words have found their way into the language from the names of people.(好像有点麽看懂这句话.)
A.how much B.how soon C.how many D.how long
Time spent on a beautiful beach can be very enjoyable_______you go for a hoilday for a visit to your friends.
A.if B.when C.no matter D.whether