A volcanic island arc forms when ________.

As a market moves from a single seller to a competitive one, a product's price _____.

Clouds release moisture on the ____ of mountains

_________ occur when the ocean's height increases and decreases periodically.

"weather" and "climate" are ________.

Charles darwin wrote about _____.

On average, developed countries spend about $________ annually per capita on health care.

Malthus noted that human populations grow ___ while food supply grows ____.

Malthus argued that ________

Large cities tend toward _______________ relationships, while smaller ones tend toward ___________.

Gender studies of migration indicate that men ______________ than women.