先天性双侧唇裂手术修复最适宜的时间是
A.生后即刻
B.3~6个月
C.6~12个月
D.1~2岁
E.2岁以后
参考答案:C
下列有机物检验方法正确的是
A.取少量卤代烃加NaOH水溶液共热,冷却,再加AgNO3溶液检验卤原子存在
B.用酸性KMnO4溶液直接检验乙醇与浓硫酸反应是否得到乙烯
C.用燃烧的方法鉴别甲烷与乙炔
D.用新制CaO检验乙醇中是否含有水分
13. The foreman(工头) beat him _____ , and the other workers were very angry with him.
A.red-blooded
B.black and white
C.red-handed
D.black and blue