题目

请阅读下面文字，并按照要求用英语写一篇150词左右的文章。A Chinese boy is reported to have spent about 2 million yuan in studying in New Zealand but failed to get any diploma. He even could not take care of himself and his grandmother had to feed him.The man in the case is a so-called adult baby, because his deeds make him almost the same as a baby. He cannot take care of himself. He is unable to go to school, let alone finish studies.He even relies on his grandmother to feed him.However, he burns money faster than any normal student. He spent about 2 million yuan in tw已知函数f（x）=x+ax（a＞0）．（I）判断函数f（x）的奇偶性并证明；（II）若a=4，证明：函数f（x）在区间（2，+∞）上是增函数．