21，Teachers should guide students to behave well at school.

22，I believe that college students should take part-time job, there are three reasons to support my opinion.

I believe that college students should take part-time jobs, and I will give three reasons to support my position.

23，He will have more opportunities in the future as long as he works hard.

He will have more opportunities in the future as long as he works hard now

24，We can use money to do a lots of things, such as travel around the world, buy cars and start our own company.

We can use money to do a lot of things, such as traveling around the world, buying cars and starting our own companies.

25，The prices of goods will continue to rise in the future.

26，The class was too boring and he was bored.

27，There are some students who don’t obey the school rules

Some students don’t obey school rules.

28，He has a lots of works to do.

He has a lot of work to do.

29，Now, people are easier to success than before.

People are more likely to achieve success now than they were in the past.

30，Government should pay more attention on improving public transportations.