Because blood from different individuals may different in the type of antigen on the surface of the red cells and the type of antibody in the plasma, a dangerous reaction can occur between the donor and recipient in a blood transfusion.

Education, whether it happens at school or anywhere else, is a important part in our life.

The Great Pyramid of Giza is said to have built over a 20-year period.

A beaver uses its strong front_teeth to cut down trees and peel_off its bark.

The Oxford English Dictionary is well known for including many different meanings of words and to give real examples.

Some of my friends are good at English while other are good at Mathematics.

He is the second person be killed in that way.

A child of noble birth, his name was famous among the children in that school.

She wishes that we didn’t send her the candy yesterday because she’s on a diet.

Once you have finished an article and identified its main ideas, it may not be necessary to reread it again.

Narcissus, a character in mythology, gazed at his own image in a pool so ardently that he fell into itself and downed.

People are not allowed enter the park after midnight because of lack of security.

Although Nam worked very hard, but he didn’t pass the final exam.

By the turn of the century, most of the inventions that were to bring in all the comforts of modern living has already been thought of.

Each of the members of the group were made to write a report every week.

If I had studied carefully, I wouldn't made so many mistakes.

Mother’s Day is the day when children show their love on their mother on.

Dogs that are trained to lead the blind must be loyalty, intelligent and calm.

It is very difficult for human beings fighting pollution.

What happened in New York were a reaction from city workers, including firemen and policemen who had been laid off from their jobs.

The world is becoming more industrialized and the number of animal species that have become extinct have increased.