3.动名词或分词结构
1） Drinking，eating，and smoking excessively can do severe harm to even a young person’s health.
2） The art of communication requires learning the language and culture of the audience.
4.递进式结构
1） Fresh vegetables are nutritious（有营养的）；furthermore，they re cheaper than frozen ones.
2） Helping others will not only bring joy into other people’s lives，but also added happiness into our own.
5.表示重要性或必要性
1） It’s important to set aside time for relaxation，hobbies ，and entertainment as well.
2） A harmonious atmosphere is essential（necessary / critical / indispensable）to achieve success.
3） Global warming can endanger our lives so much that we are obliged to make a careful study of the problem and try to find out a lasting solution to it.
6.表示目的
1） The purpose of a test is to show what you have leaned about a subject.
2） The intent is not to catch everyone but rather to catch enough to spread the word.
3） Competitive sports are recommended to young adults to prepare them for the competitive world of college and business.
7.表示结果
1） Too much work and too little rest may lead to loss of health.
2） If you try to learn too many things at a time，you may get confused.