多用who(指人)、which(指物)、that(即可指人也可以指物)，还有一个经典的容易被忽视的定语从句在大作文中可以表达事件发生的原因：即由why引导的固定句型...the reason(s) why...
There may be some reasons why entertainment stars earn high salaries but overall I agree that they are overpaid.
文章中提出观点的好句型，无论是你自己的观点还是文章中原来给出的观点都可以。建议多用that引导的，不容易出错，如：some people think/agree/suggest/insist that...
A growing number of parents believe that being overly dependent on social networking websites only makes their children more isolated in the real world.
The related sectors should take effective measures the moment the problem appeared.
Generally，air will be heavily polluted where there are factories.
As this policy would also affect the cost of public transport, it would be very unpopular with everyone who needs to travel on the roads.
D.条件状语从句(引导词：if/as long as/providing that/provided that...)
The government will increase its support for public education, provided that such funds can be put to good use.
E.让步状语从句(就是转折关系，引导词：though/although/while/no matter who/where/which/how...)
*While (表示二者对比)some people link happiness to wealth and material success, others think it lies in emotions and loving personal relationships.
*Even though it is unlikely that all workers do feel happy in their work, I think it is not unrealistic to promote more job satisfaction in any job.