例：Bad books contain evil thoughts. In them, there might be much description about violence, superstition, and sex.
→ Bad books, in which there might be much description about violence, superstition, and sex, contain evil thoughts.
1. 原因状语从句：常由because, as, since和for引导
例: Nonetheless, I am still in favor of space travel, for its merits far outweigh demerits.
2. 让步状语从句：常由although, though, even though/ if, as long as和notwithstanding引导
例: Although this view is wildly held, this is little evidence that education can be obtained at any age and at any place.
3. 条件状语从句：常由if, on the condition that和providing that引导
例: If you want to achieve something or intend to fulfill one of your ambitions, you must work hard, make efforts and get prepared.
例: When it comes to education, the majority of people believe that education is a lifetime study.
5. 目的状语从句: 常由so that和in order that引导
例: Millions of people have to spend more time and energy on studying new skills and technology so that they can keep a favorable position in job market.
例1: Some people claim that government should be mainly responsible for the environmental pollution.
例2: Many experts point out that, along with the development of modern society, it is an inevitable result and there is no way to avoid it.
例1: It is an undeniable fact that environmental pollution becomes increasingly serious.
例2: No one can deny the basic fact that it is impossible for average workers to master those high-technology skills easily.
例1: What has caught our attention is /It is noticeable that the environment in both the rural and urban areas is deteriorating.
例2: It is universally acknowledged that environmental pollution becomes one of the most serious problems in China or even the world as a whole.
It is + 被强调的内容 + that
例: It is cars and factories that release a great deal of gases, polluting the environment.
例: Only if the government take some appropriate measures, will this intractable problem be tackled.
例: Every means should be tried to protect the environment on which people live.
例1: Tourism, which is a rising industry, has become the major source of economy, playing crucial role in many Asian countries.
例2: To be more specific, government should stage some relevant laws or regulations to severely punish the factory producing a great number of pollutants and the people littering or spitting deliberately.
例1: Computer, an indispensable part in our life, has brought us great conveniences.
例2: College students, lacking social experience, are easily cheated.