Questions 1-2 are about the following passage.

    The Sahara Desert is the world's largest hot desert. The Sahara is in North Africa and is as large as the United States. Many people think that an area like this has no animals or plant life, but they are incorrect. In fact, the Sahara Desert has many different "ecoregions." Each ecoregion has different plants and animals living there. The biggest ecoregion is called the "Sahara Desert ecoregion." In this area, the climate is extremely dry and extremely hot. The landscape is sandy and dusty with many high dunes.

    Because the Sahara Desert ecoregion is so hot and dry, there are very few plants and animals. Scientists estimate that there are only 500 species of plants. This is not very much when thinking of how enormous the region is. These plants include acacia trees, palms, spiny shrubs, and grasses. The Sahara is also home to 70 species of mammals. Twenty of these are large mammals. There are about 90 species of birds and around 100 reptiles.

    The biggest threat to plants and animals in this environment is drying up. Because of this, plants have the ability to recover their health after their leaves have dried out completely. Animals can lose 30.60% of their body mass and still survive. Most animals do not get their water from drinking like in other ecosystems. Instead, they have adapted to get their water through metabolic procectes. This is why they can survive in a place like the Sahara Desert ecosystem.