life will continue on the earth for millions of years to come will depend on this problem

问题补充：

life will continue on the earth for millions of years to come will depend on this problem can be solved.

A. Whether; that

B. That; why

C. Thathow

D. Whether; whether

答案：

A. Whether; that

B. That; why

C. Thathow

(答案→)D. Whether; whether

解析：