快要考试啦,时间紧啊。
1,well, in paragraph 2 if a survey or statistics are provided your point will be more convincing.
2,paragraph 3's experiment conducted in US is quite good.but, details about which college and voices about some subjectives will increase the credibility of your example.
3,the main point of paragraph 4 seems too complicated, as you have many ideas to express in one paragraph. right?