it‘s+adj+to do 和it+adj+to do sth 有什么用法

题目

it‘s+adj+to do 和it+adj+to do sth 有什么用法
举个例子

答案

1 It is important to drink enough water every day.
it形式主语,没有意思的,to drink enough water every day真正主语,意思是：每天喝足够的水很重要.你看,主语那么长,而谓语就is important 那么短,是不是头重脚轻啊,为了句子平衡,使用了形式主语,而把真正主语放在后面,所以句型：it‘s+adj+to do 的意思是：做某事怎么样.
2 Doctors think it is important to drink enough water every day.
这时候It is important to drink enough water every day.
是宾语从句,作think的宾语.因为think 可以形成think+ 宾语+宾语补足语,所以此句可改成Doctors think it important to drink enough water every day.
也就是少了be动词is.此时,it是形式宾语
important为宾语补足语to drink enough water every day为真正宾语.
能这样用的,除了find外,常见的还有：find,believe等