Fire-resistant materials are used to retard ________ of modern aircraft in case of accidents.

Because the United States does not have much oil anymore, imported oil ________ used more and more.

The FDA was set up in 1940 ________ that maintain standards for the sale of food and drugs.

If a ruby is heated it ________ temporarily lose its color.

Robots are being used increasingly in industry as they can work on large jobs faster, are more precise and ________.

The algebra of sets ________ Boolean algebra.

That magnificent ________ temple was constructed by the Chinese.

________ the formation of the Sun, the planets, and other stars began with the condensation of an interstellar cloud.

________ in Shanghai than in any other city in China.

That most natural time units are not simple multiples of each other ________ in constructing a calendar.