is well known Hong Kong returned to China on July 1st, 1997. A. It, that B. As,
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_______ is well known _______ Hong Kong returned to China on July 1st, 1997.
A. It, that B. As, /
C. As, as D. It, which
试题答案
A
it 为形式主语，其后的that从句为主语从句。