was known to them all that Bob had broken his promise he would give them a rise.A. As; w

问题补充：

was known to them all that Bob had broken his promise he would give them a rise.

A. As; which

B. What; that

C. It; that

D. It; which

答案：

A. As; which

B. What; that

(答案→)C. It; that

D. It; which

解析：此处It为形式主语,第一个that引导主语从句,第二个that引导同位语从句。