（十三）You may think there is only sand in the desert of the world, _1_ it is not true. In the desert, as we know, there is a little _2_, but it is not _3_ for most plants. Still we can see some plants _4_ in the desert.There is _5_ in some places in the desert. We _6_ these places oases. In the oases, there are villages and towns. People grow _7_ kinds of crops in the fields there.People _8_ live outside the oases. They have camels, sheep and other animals. These animals depe
