题目

动词考查；选择恰当的动词填空 I know you are from China. Can you________ English?     A. speaks      B. speaking   C. speak      D. to speak 答案：C 4．已知x，y满足约束条件$\left\{\begin{array}{l}{x+y-2≤0}\\{x-2y-2≤0}\\{2x-y+2≥0}\end{array}\right.$，若对于满足约束条件的所有x，y，总有不等式y≤k（x+3）成立，则实数k的最小值为（　　）A．$\frac{1}{2}$B．$\frac{2}{3}$C．-2D．0