四、短文填空。
根据短文内容，从方框中选出最佳的词，并用其适当形式完成短文。
big you hot large quick cold live cover rain million
Can you imagine a sea of sand three times 1. than India? This is the Sahara Desert, the 2. desert in the world. It 3. 11 countries in North Africa and is over 9 4. square kilometers. That's more than 25% of Africa.
In the Sahara, temperatures are very different during the day and at night. It is much 5. during the day. The hottest time is between 2 p.m. and 4 p.m., when temperatures rise to 38℃. But it is very cold at night—the coldest time is at 4 a.m., when temperatures fall to -4℃. The Sahara is also very dry. It seldom 6. . Because of the temperatures in the desert, it is a very difficult place 7. .
During the day, cover 8. body, head and face. Clothes protect you from the sun and keep water in your body. You will also need a warm blanket at night. It can get cold more 9. . When the temperature drops, it can be a shock and make you feel even 10. .

1.bigger 2.largest 3.covers
4.million 5.hotter 6.rains 7.to live
8.your 9.quickly 10.colder