The deserts of the world are not al

The deserts of the world are not all covered with sand. Many of them have surfaces of rock or clay or small stones. They are not flat, either; they often have high hills and deep valleys. There is some plant life in many parts of the desert. There is little rain in the desert, but it does fall often enough for most plants.
The deserts of the world are not uninhabited. People also live outside oases, but these people are not farmers. They have camels, goats, donkeys, sheep, etc. These animals can live on the desert plants and do not need much water.
The people of the desert have to move constantly from place to place, they must always look for grass or desert plants for their animals. They usually live in tents. When there is no more food for their animals, they fold up their tents, put them on their camels and donkeys, and move to another place. In good years, when there is not enough food for their animals, they trade their skins and their goats and camel hairs with the people of oases for wheat and fruit. But in bad years, when there is not enough food for their animals, the people of the desert would attack the oases people. But they are also hospitable. No man in the desert would ever refuse to give a stranger food and water.

Câu 25: According to the passage, deserts are mostly made up of__________
A. sand B. clay C. stones D. rock
Câu 26: The underlined word "hospitable" has the meaning of being________
A. brave B. kind C. cruel D. strange
Câu 27: In the desert_____________________
A. it rains for a short time every month B. it rains in spring only
C. there is some rain, but far from enough D. the rainfall is just enough for the plants
Câu 28: People live ____________
A. only outside the oases B. both inside and outside the oases
C. only inside the oases D. in places with regular rainfalls
Câu 29: From the passage we know that life ____________
A. is impossible in deserts B. is happy in deserts
C. is hard in deserts D. in deserts is much better now