某男,外伤后意识丧失,呼吸困难,急救时人工呼吸吹气量一般是
A.不少于600mlB.不少于1000mlC.不超过1000mlD.不超过800mlE.不少于800ml
参考答案:E
Two years has passed since I _____ you the first time. [ ]
A. meet
B. have met
C. met
D. had met
(6分)根据要求写出名称或结构简式:
(1) 名称:
(2)3-甲基-1-丁烯 结构简式:
(3)2,2,4—三甲基戊烷 结构简式: