IV. Read the following passage and choose the best answer for each blank.

The Middle East and North Africa are one of the driest regions on earth. Nearly two-thirds of the region is desert. The Sahara Desert of northern Africa is the largest desert in the world. Desert air (26) ____ little moisture, so few clouds form over the land. Without clouds to block the sun, temperatures may reach as (27) ____ as 125°F during the day. At night, without the clouds to contain the heat, the temperature can fall to as low as 125°F. Extreme temperatures (28) ____ with little rainfall make desert life difficult for people, plants, and animals. (29) ____, some life forms have adapted to even the most severe desert (30) ____, Camels are able to survive long periods without food or water. Many desert plants have long, shallow (31) ____ systems. This allows the plants to reach out to collect water over great distances. Other desert plants have taproots. Taproots grow very deep (32) ____ they can tap sources of underground water. Plant life in the desert is usually spread out over great distances. This is (33) ____ deserts are often described as barren, or lifeless.

When many people think of a desert they often think of endless miles of hot sand, but a desert does not have to be hot or sandy. Most of the land of the Middle East and North Africa is hot, dry desert land, (34) ____ some deserts look very different. Most of Antarctica is a desert but there is no sand on the continent and the climate of Antarctica is (35) ____ coldest on earth.

Extreme temperatures (28) ____ with little rainfall make desert life difficult for people, plants, and animals.