11，work 后面的介词改成at Work at home is better than work at the office

12，go改成going I go to school by car everyday.

13，healthy改成healthier are 改成 was The food in the past was healthier

14，person改成people Many people can make many money today.感觉怪怪的。

15，Because it can save a lot of time , so many people choose to work at home to use computers rather then work in the office. Because it can save a lot of time, many people choose to work at home using computer rather than to work in the office

16，There are many high school students choose to work and travel a period of time before they going to college.

Many high school students choose to work and travel a period of time before they go to college./before going to college

17，Students can experience different cultures when they study abroad. For example, they can experience the unique lifestyles, traditions and customs in other countries.

18，Young children are likely to be cheated

19，没看出有什么问题

We can acquire much knowledge and information on the Internet.

20，Technology may bring many problem to our society

Although technology may bring many problems to our society, it…