1. that引导的从句e.g. It is reported that one third of Guangzhou citizens plan to buy a private car.
2. whether/if引导的从句e.g. Whether motorcycles should be banned in Guangzhou has become an issue of controversy。
3. how/why/when/where引导的从句e.g. This essay aims to explore why so many white collar workers suffer from insomnia.
4. who/whom/whose/what/which引导的从句e.g. Who should be responsible for the environmental degradation is still unknown。
由关系代词who, whom, whose, that, which, as引导的从句。例如： People who are strongly against human cloning claim that it is immoral and unethical.
由关系副词when, where, why引导的从句。例如： I would like to analyze the reasons why a growing number of teenagers are addicted to gambling。