①f（x）=sin2x； 

②g（x）=x³；

③h（x）=（ $\frac{1}{3}$ ）^x；

④φ（x）=lnx．

其中是一阶整点函数有（   ） 个．

短文改错

假定英语课上老师要求同桌之间交换修改作文，请你修改你同桌写的以下作文。文中共有10处错误，每句中最多有两处。错误涉及一个单词的增加、删除或修改。

增加：在缺词处加一个漏字符号(Λ)，并在其下面写出该加的词。

删除：把多余的词用斜线(＼)划掉。

修改：在错的词下划一横线，并在该词下面写出修改后的词。

注意：

1）每处错误及其修改均仅限一词；

2）只允许修改10处，多者(从第11处起)不计分。

My brother used to ask me question whenever he did his homework, that made me annoyed. But every time he accepted my explanations I feel that I was the smartest person in the world. Answered his questions, I always liked to say that he was so stupid to solve such simple problems.

Last week both of them got the report cards from our school. Unexpectedly, I got a lot of Bs, though he got As. To make things worse, all that day my brother screamed how foolish it was for me not to ask questions! I could say nothing but admit that he was right. I have never made a fun of him since then.