i think it is very important to do something.&i think it very important to do sth.

题目

i think it is very important to do something.&i think it very important to do sth.
两个句子都对吗?
区别在哪里呢

答案

都对.
第一句中it is very important to do something作think的宾语从句.
第二句中it作形式主语