If you write too many simple sentences, your writing will be monotonous (单调的) and unlively (无生气的). Besides, simple sentences cannot possibly convey the complicated (复杂的) things you want your reader to know. So you should turn to complex sentence for help. A complex sentence consists of one independent or main clause and one or more dependent clauses.

Identify the clause that is dependent on the other.

Because she has made up her mind to be a teacher, her reading circles around the approach to teaching.

The dependent clause Because she has made up her mind to be a teacher just tells a reason for the main sentence. That is, the clause is one part of the main sentence. It may be safely concluded that all the dependent clauses in complex sentences serve as parts of the main sentences.

1. Relative clauses (关系从句): they are clauses that serve as noun modifiers (名词修饰语).

1) All that glitters is not gold.
闪光的并非都是金子。

2) Oxygen in which fires burn is a colorless gas.
氧气是一种无色的气体，火可以在其燃烧。

3) The senator spoke strongly against the man who opposed his idea for a new law.
参议员对那些反对他制订新法的人措辞强硬。

4) The sea was, unfortunately, very rough the day we crossed the channel.
很不幸，我们穿越海峡的那天，海面风高浪急。

Exercise:

Combine the following pairs of sentences, turning one into a relative clause with or without a relative pronoun (关系代词).

1. I am very surprised that she left her father at such a time.
/ He was very ill at that time.

2. He introduced me to his students.
/ Most of them were from abroad.

3. Thank you for the birthday gift.
/ You sent me the gift last week.