It is possible for a chemist to use the melting point of a particular substance to determine its purity.

The campers heard a strange rustling in the trees.

Mark cannot talk well because he has a speech impediment.

The cheetah is considered the fastest of all land animal.

Fainting, or a temporary loss of consciousness, may be brought about by an insufficient supply of oxygen to the brain.

A balance of international payment refers to the net result of the business which a nation carries on with other nations in a given period.

In an annulment, a marriage is declared invalid.

When Benjamin Franklin became the first American postmaster general in 1775, he worked to improve the frequency and reliability of mail delivery.

Carbon monoxide prevents hemoglobin from supplying oxygen to the body.

Paul increases the income from his scholarship by working part-time on campus.