题目

Timothy Doner has an unusual hobby—He likes to learn languages. Over the last five years, the 17-year-old boy has been able to master 23 languages. He becomes the youngest polyglot(通晓多种语言的人) in the world.He began to learn languages in 2009 after completing basic Hebrew(希伯来语的) lessons. He enjoyed it so much that he decided to become fluent( 流利的 ) in Modern Hebrew. After that, there was no stopping because he loved languages so much.Over the years, he has added eighteen kinds of languages to his list of languages. The list doesn’t include French, Mandarin, Lat13．设f（x）是定义在R上的奇函数，f（2）=0，当x＞0时，有xf′（x）-f（x）＜0恒成立，则xf（x）＞0的解集为（　　）A．（-2，0）∪（2，+∞）B．（-2，0）∪（0，2）C．（-∞，-2）∪（2，+∞）D．（-∞，-2）∪（0，2）