制定饮用水卫生要求的流行病学意义就是确保不发生（）
A.急性胃肠炎
B.食物中毒
C.介水传染病
D.急性中毒
E.水型地方病
参考答案：C
— Why are you standing outside the gate?
— My father me wait for my aunt from the country here.
A．asked
B．ordered
C．made
D．kept
协同刺激信号
