Tom is seven . He goes to school every day .The school is near his home , so he goes there on foot and comes back home on time . But today he is late .his mother asks his , “Why are you late today?”“I am in the headmasters office?”“Why do you go the headmaster's office?”“Because my teacher asks us a question in the class , nobody (没人)can answer(回答)it , but I can .“It's good to answer the teacher's question.”“But the question is who pus ink on my chair.”

说出下列句子的修辞手法。

在那天边隐约闪亮的不就是黄河？那在山脚缠绕不断的自然是汶河，那拱卫在泰山膝盖下的无数小馒头，却是沮涞山等著名的山岭。

已知a+$\frac{1}{a}$=5，求$\frac{a^4+a^2+1}{a^2}$的值．

下列各组对话中，语言表达得体的一项是 (    )