Ecologists are trying to preserve our environment for future generations by protecting the ozone layer, purifying the air, and have planted the trees that have been cut down.

A warning printed on a makeshift lifebuoy says: “This is not a life-saving device. Children should be accompany by their parents.”

The bones of the elderly are more prone to fractures than of young people.

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.

Building thousands of years ago, the ancient palace is popular with modern tourists.

Robots in the home might not be enough creative to do the cooking, plan the meal and so on.

We had better to review this lesson carefully because we will have some questions on it.

Proteins are made up of folded irregularly chains, the links of which are amino acids.

The US, that is one of the most powerful countries, decided to declare a war to Iraq.

David, who mother is Vietnamese, speaks both Vietnamese and English fluently.

Anyone reproducing copyrighted works without permission of the holders of the copyrights are breaking the law.

In most countries music songs are deeply personal and deal with themes of love, lonely, and separation.

Neither of the men arresting as terrorists would reveal information about his group.

Practicing his speaking English everyday, his hope was to get a good job in a foreign company.

When precipitation occurs, some of it evaporates, some runs off the surface it strikes, and some sinking into the ground.

Doctors believe there is better in this modern world of ours to try to prevent illnesses than to rely on medicines to cure them.

Unlike the old one, this new copier can perform their functions in half the time.

The deadbolt is the best lock for entry doors because it is not only inexpensive but installation is easy.

Instead of calling off the meeting, maybe we can just put it over until next month.

Mary and her sister just bought two new winters coats at the clearance sale.

The chief of police demanded from his assistants an orderly investigation, a well-written report, and that they work hard.