单选题 ______ was known to them all that William had broken his promise ______ he would give each of them a gift.
   A) As; Which     B) What; that   C) It; that      D) it; which
【正确答案】 C
【答案解析】第一空填it，为形式主语；第二空填that，用以引导一个同位语从句，修饰promise。