问题补充:
was known to us all that Johnson had broken his promise he would give each of us a small gift.
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:第一空it作形式主语,真正的主语是that Johnson...;第二空that引导的是同位语从句,用以解释promise的内容。