纯苯、甲苯、二甲苯可称作（）。
A.同分异构体
B.同系物
C.同一物质
参考答案：B
95599客服中心运营部（）固定召开例会。
A、每天
B、每周
C、每月
D、每季
Ben usually goes to Greece for vacation, but this time he wants to do _________.[ ]
A. different something
B. anything different
C. something different
D. different anything
