病人呼吸骤停后,最简单且有效的建立人工呼吸的方法是()
A.麻醉机
B.人工呼吸机
C.气管插管呼吸
D.简易气囊呼吸器
E.口对口人工呼吸
参考答案:E
His grandfather _____for thirty years. [ ]
A. died
B. was dead
C. has been dead
D. has died
一种气态烷烃和一种气态烯烃的混合物共10g,平均相对分子质量为25。使混合气通过足量溴水,溴水增重8.4g,则混合气中的烃分别是 [ ]
A. 甲烷和乙烯
B. 甲烷和丙烯
C. 乙烷和乙烯
D. 乙 烷和丙烯