题目

已知f()=，那么f(x)的解析式为(    ) A.          B.             C.            D.1+x 答案：思路解析：令u=，x≠0且x≠-1，则x=，u≠0，u≠-1.∴f(u)=(u≠0，且u≠-1),即f(x)= (x≠0且x≠-1).答案：C18.  ( 2013 江办无锡江阴，6) —Did you hear that we would have teaching building?   一Really? I'm happy to hear that.   A. another;built   B. the other;to building   C. another;to be built   D. other;built