采用戊烯二醛反应鉴别尼可刹米时,需用试剂有( )
A.氨制硝酸银试液B.香草醛试液C.0.14%庚烷磺酸钠溶液D.β-萘酚碱性液E.溴化氰试液与2.5%苯胺溶液
参考答案:E
When we passed by the shop, we heard someone ________ for help. [ ]
A. called
B. calls
C. is calling
D. calling
在许多东方国家,()是常见的传统礼节。
A.拥抱
B.握手
C.鞠躬
D.亲吻