it作形式主语的句型 — 英语选择题
题目
下列句子中，it 作形式主语的一项是（ ）
A. He found it interesting to visit the Great Wall last summer.
B. It is said that the Palace Museum attracts millions of visitors every year.
C. This is important for us to learn more about Asian cultures.
D. I think it necessary that we should know something about Thailand.