The geographic position of North America, ________ in the early days of the European settlement.

Often a team of engineers are ________.

Most insurance agents would rather you ________ anything about collecting claims until they investigate the situation.

Only one mammal, ________ is known to bear routinely four identical young.

The Appalosa horse was brought to Mexico from Spain, was later introduced into the United States, and today ________.

Cuba is ________sugar-growing areas in the world.

Not every pearl that is found ________.

The bacteria in milk is destroyed when ________ to at least 62¦C.

The growth of two-income families in the United States ________ of people moving to a new social class.

Although it is difficult ________ , a frog is more likely to be smooth and wet, and a toad rough and dry.