Air is to us _____ water is to fish.

A. what    B. that       C. which    D. is that

 Air is to us _____ water is to fish.

A. what    B. that       C. which    D. is that

 Air is to us ____ water is to fish.

    A. that       B. which     C. it          D. what

Air to us is _____ water to fish.
    A.what         B.that            C.which           D.of which

Air is to us　 water is to fish.

A、is that　　 B、what　　 C、which　　 D、that