The Sahara Desert in Northern Africa is the largest hot desert in the world. It is about 1，800km from the north to the south and about 4，800 km from the east to the west. Temperatures can reach 58℃ in the daytime and can fall to ﹣6℃ at night. More than 8，000 years ago，the Sahara was a rich land where farmers grew food and plants grew well. As the rainfall in the area gradually went down every year，it became a huge desert. Most areas of this desert have less than 13 cm of rain every year.
Gary Smith and a few of his brave friends decided to hike across the Sahara. Supporters in cars，who carried food and water for the group，stayed with them together.
One day，Smith walked alone and then he couldn't find the rest of the group. Even worse，he could not find out which direction to go. Then a sandstorm covered the area. When the storm was over，Smith was even more worried. In the heat that he couldn't stand，he quickly finished his water. He had to spend that night out in the open，and he almost felt he couldn't survive （生存）.
The next day，he walked on. After the second night，he started to worry about dying. He realized that his friends might not find him in time. It was late on the third day that Smith lost his sense and fell over.
When Smith awoke，he was in the car with his friends. He had been found by a group of Bedouin who were traveling in a truck. In such a large desert with the weather conditions， this made it possible for him to survive. Then Bedouin returned to his group of friends. Smith was so lucky.
