Question

We all think ________ helpful for our study to have a break at the weekends.

1. A.
   it
2. B.
   that
3. C.
   this
4. D.
   /

Answer 1

A
解析：本题谓语动词是think，空格后是形容词短语，而最后是不定式短语，help for our study指的是不定式短语to have a break at the weekends，因此这个不定式是动词think的宾语，故空格中应填一个形式主语；而选项中可以用作形式主语是it，因此A为正确答案。