适用于集中式生活饮用水水源地、二级保护区、一般鱼类保护区及游泳区（）
A.Ⅰ类水
B.Ⅱ类水
C.Ⅲ类水
D.Ⅳ类水
E.Ⅴ类水
参考答案：C
We missed our train, and ________ the next train was delayed, ________ we had to wait for another two hours.
A．on top of that; so
B．as a result; thus
C．what was worse; therefore
D．apart from that; then
下列哪些因素可以诱发舌后坠（）
A.催眠药
B.麻醉药
C.肌松药
D.脑外伤
E.颈段硬膜外阻滞
