if I buy some language books, I think these are very most important things to me. 1. The books is not too difficult to understand, and they must be very imteresting, for example, there are many pictures in the books, the words are very humour, and so on. 2. There are many things about real life in the books, and then I can learn from it and use it into the reality, for example, the sentences are used when the foreigners use in the public.. 3. At last, I will select some bookds about history, novel and so on. But they are not very difficult.