题目

选出不同类的单词。【1】A.train B.friend C.bike【2】A.letter B.swim C.play【3】A.look B.at C.to【4】A.near B.station C.up【5】A.take B.this C.write 答案：【答案】【1】B【2】A【3】A【4】B【5】B【解析】【1】略【2】略【3】略【4】略【5】略16．解方程：①$\frac{1}{x-3}+2=\frac{4-x}{3-x}$②$\frac{4}{{x}^{2}-1}-\frac{x+1}{x-1}=-1$．