A. We find high youth unemployment a problem in the USA.

B. It is the USE that has a great number of young people.

C. High youth unemployment is found in the USA.

D. The USA is a country of young people.

A. In spite of being busy at work, my mother takes good care of her children.

B. My mother takes good care of her children but she is very busy at work.

C. Though my mother was very busy at work my mother took good care of her children.

D. Although my mother was very busy at work she did not take good care of her children.

A. She said me to think carefully before applying for that job.

B. She says me to think carefully before applying for that job.

C. She advise me to think carefully before applying for that job.

D. She advised me to think carefully before applying that job.

A. The plants which live on that island may develop differently.

B. The plants live on that island may develop differently.

C. The plants which lives on that island may develop differently.

D. The plants which live that island may develop differently.

A. Some kinds of fish live in fresh water, for others live in sea water.

B. Some kinds of fish live in fresh water, and others live in sea water.

C. Some kinds of fish live in fresh water, or others live in sea water.

D. Some kinds of fish live in fresh water, so others live in sea water.