【C3】A．whatB．whenC．thatD．where

【C19】______A．whichB．whenC．thatD．where

【C2】A．whereB．whenC．thatD．which

Air is to men______water is to fish.A．whatB．whenC．thatD．which

There are many animals, however, ____ never play.A: whatB: whichC: thatD: where

【C8】A．whatB．whoC．thatD．where

【C10】A．whileB．whenC．thatD．which