The twins look the same. Mr Li find hard to tell one from the other.A it B them C her D t

问题补充：

The twins look the same. Mr Li find hard to tell one from the other.

A it B them C her D that

答案：

解析：：考查it作为先生宾语用法。英语中只有it可以作为形式主语，形式宾语。本句的it是形式宾语，真正的宾语是不定式to tell one from the other.故A正确。