题目lim _(x arrow 0) (3-sqrt(x y+9))/(x y)=A. (1)/(6)B. -(1)/(6)C. 0D. 极限不存在$\lim _{x \rightarrow 0} \frac{3-\sqrt{x y+9}}{x y}=$A. $\frac{1}{6}$B. $-\frac{1}{6}$C. 0D. 极限不存在题目解答答案D. 极限不存在