Don't you think of great importance that we should keep fit by taking exercise regularly?A

问题补充：

Don you think of great importance that we should keep fit by taking exercise regularly?

A. this

B. that

C. which

D. it

答案：

A. this

B. that

C. which

(答案→)D. it

解析：可联系答.案.网客服索取。