可用来鉴别己烯、四氯化碳、苯的试剂是
A．硫酸
B．溴水
C．乙醇
D．盐酸
答案：B
溴水使己烯褪色，和四氯化碳、苯都萃取，一个溴在下层一个溴在上层。
若a和b均是整型变量并已正确赋值，正确的switch语句是（ ）。
A．15
B．50
C．55
D．5
The man who hit so many people in a row had drunk so much that his mind could no longer distinguish ________ fantasy and reality.
