well known to the Irish is St. Patrick was taken to Ireland as a prisoner when he was 16.
A. It, that
B. As, what
C. That, what
D. What, that
网友回答
(答案→)A. It, that
B. As, what
C. That, what
D. What, that
解析：原句意思是，爱尔兰人都知道，帕特里克在他十六岁时，作为囚犯，被带到了爱尔兰。it 是形式主语，后边that引导的从句是句子的真正主语，所以选A。