Question

这个句子成分怎么分析？

It will be difficult to make them really think like a human

Answer 1

这个是典型的it形式主语的主系表结构。
(真正的)主语是to make them really think like a human，will be是系动词将来时，difficult是形容词作表语。
句子可以还原成：To make them really think like a human will be difficult.

Answer 2

it 形式主语
will be 系动词
difficult 表语
to make them really think like a human 动词不定式做真正的主语
之所以把真正的主语放后面是为了避免头重脚轻

Answer 3

it作形式主语，不定式作真正的主语。