二、将下列各组简单句组成复合句：

例如：The gentleman lives here.

He is her brother.

合并为：The gentleman who lives here is her brother.

1.I was reading. She was writing.

1. In Mr. Wang's house I met several college students.

All of them were engaged in revolutionary work.

1. The English language is difficult.

It is less difficult than the Russian language. Its grammar is much simpler.

1. Science is useful.It can benefit mankind.It is also dangerous.

Used by evil-doers it can bring harm to people.