题目

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 plants’ 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(not lived by people). People also live outside oases(绿洲), 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 p8．如图是A、B、C三种物质的溶解度曲线，看图回答下列问题：（1）P点的含义是在t1℃，A、C的溶解度相等．（2）青海盐湖地区有一种说法，“冬天捞碱，夏天晒盐”．其中“碱”的溶解度曲线与图中A 物质的溶解度曲线相似．