选词填空

You may think there is nothing but sand in the desert of the world, but it is not true. In the desert we can____ stones. We can see hills, too. There is a little rain in the ____  , but it is not____  for most plants.
　　The animals are ____ to the desert people in many ways. The desert people eat the meat and drink the milk of the animals. They use their skins to ____ shoes, water bags and even tents(帐篷). They use the camels(骆驼) for____  things.
The people of the desert have to keep ____  from places to place. They must always look for grass or desert plants for their animals. They usually live in the tents. When there is mo more food for their animals, they take down their tents, put them on the camels and move to ____ place. The desert people are very____ . No man in the desert would ever refuse to help the people in ____  and give them food and water

如图所示，在平底烧瓶内装有少量的水，用打气筒向瓶内打气，观察到许多物理现象，其中分析错误的是（　　）