What was life like on earth for most of its history

Where does the availability of water pose the greatest problem

According to the earth science reference tables, during which geologic time period were the continents of north america, south america, and africa closest together?

Compared with the land in the highlands, the lowlands region of england a) rockier and more difficult for farmingb) the center of business and industryc)richer in coal reservesd)covered by more fertile farmland d) covered by more fertile farmland