呕吐本身对人体有保护作用
A．排出过多的液体B．排出过多的钠盐C．排出胃内有毒物质D．排出过多的血钾E．使胃肠通畅
参考答案：C
-Look! That teacher is explaining something to her students again and again!
-_______teacher she is! [ ]
A. How patient
B. What patient
C. How a patient
D. What a patient
旅游者旅行回国后如感不适，入境（）日内，必须到就近的卫生检验机关进行必要的健康检查和咨询，同时应向医生讲明自己的旅行史。
A.15
B.30
C.40
D.45
