Little have people done to alleviate the sea pollution caused by the factories in central Vietnam, haven’t they?

Reading several books on that subject, Bill considered himself an expert.

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

The big problem was that we really did not understand what was happened

Working provide people with personal satisfaction as well as money.

Society uses such human emotions as proud, shame, guilt, and fear to maintain itself.

There are many reasons why a particular species may become endangering.

The earth is the only planet with a large number of oxygen in its atmosphere.

In very early times, people around the fire were entertained by storytellers with stories of heroes’ wonderful actions and victory.

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

Everyday in summer, but especially at the weekends, all kinds of vehicles bring crowds of people to enjoy the various attraction.

I am now in my attempt winning a place at the same university to my brother.

My sister told me that she had met my teacher at the supermarket yesterday.

It is very difficult for her to prevent him for smoking in her house.

By measuring the color of a star, astronomers can tell how hot is it.

Mai and Lan have a row because they have misunderstood one another.

Despite America’s affluence, many people are without jobs, on welfare, and have a lot of debts.

Ours brains are incredibly agile machines, and it's hard to think of anything they do more efficient than recognize face.

His health gets good and better because he does gymnastics regularly.

Women in many parts of the world have had lower status than men, which the extent of the gap between genders varies across cultures and times.

If you take the train, it would be much more convenient.