is known to us all is that the Olympic Games will take place in Rio de Janeiro.A. It

问题补充：

is known to us all is that the Olympic Games will take place in Rio de Janeiro.

A. It

B. Which

C. As

D. What

答案：

A. It

B. Which

C. As

(答案→)D. What

解析：可联系答.案.网客服索取。