We cannot figure out _______ quite a number of insects, birds, and animals are dying out.?

A. that B. as?

C. why D. when?

We cannot figure out____________quite a number of insects, birds, and animals are dying out.

A.  that          B.  as           C.  why            D.  when

We cannot figure out_______quite a number of insects,birds,and animals are dying out.

A.that                   B.as                     C.why                   D.when

We cannot figure out ________ quite a number of insects, birds, and animals are dying out.    

A. that                  B. as                    C. why                D. When

We cannot figure out ____quite a number of insects, birds, and animals are dying out.

A.     that  B. as  C. why  D. when

We cannot figure out _______ quite a number of insects, birds, and animals are dying out.?

A. that B. as C. why D. when?

We cannot figure out ____quite a number of insects, birds, and animals are dying out.

A.     that  B. as  C. why  D. when

 We cannot figure out ______ quite a number of insects, birds, and animals are dying out. A. that    B. as         C. why       D. when

We cannot figure out ______ quite a number of insects, birds, and animals are dying out. [北京2004]

A. that　 　 B. as　 C. why　 D. when