[解析]
(1)America.细节理解题.根据第二段"In America, many people have three names"可知,这个男孩来自美国,故答案为:America.
(2)Alan Brown or Alan.细节理解题.根据第二段"You may call me Alan Brown or just Alan."可知,我们可以称他为Alan Brown或者Alan,故答案为:Alan Brown or Alan.
(3)grandfather.细节理解题.根据第二段"My father loves my grandfather very much, so he use J.as my middle name."可知,这个男孩的父亲给这个男孩的中间名用J,是为了记住这个男孩的祖父,故答案为:grandfather.
(4)middle name.根据第三段"You don't have the middle name."可知,中国人的名字里没有中间名,故答案为:middle name.
(5)learn Chinese.根据第三段"I hope you can help me learn Chinese."可知,本文介绍了这个男孩希望他的新朋友能帮助他学习汉语,故答案为:learn Chinese.