下列函数在其定义域内连续的是
A
$f(x)=\ln x+\sin x$ ．
B
$f(x)= \begin{cases}\sin x, & x \leqslant 0, \\ \cos x, & x>0 .\end{cases}$
C
$f(x)=\left\{\begin{array}{cc}x+1, & x < 0, \\ 0, & x=0, \\ x-1, & x>0 .\end{array}\right.$
D
$f(x)=\left\{\begin{array}{cl}\frac{1}{\sqrt{|x|}}, & x \neq 0, \\ 0, & x=0 .\end{array}\right.$
E
F