(2011)函數(shù)的可去間斷點(diǎn)的個數(shù)為:()
設(shè),則x=0是f(x)的:()
設(shè)函數(shù),若,f(x)在點(diǎn)x=1處連續(xù)而且可導(dǎo),則k的值是:()