水溶性环糊精衍生物是（）.
A．γ-环糊精
B．甲基-β-环糊精
C．α-环糊精
D．乙基-β-环糊精衍生物
E．β-环糊精
参考答案：B
若变量x、y已正确定义并赋值,以下符合C语言语法的表达式是【 】。
A．++x,y=x--
B．x+l=y
C．x=x+10=x+y
D．double(x)／10
----Excuse me, sir. Could you tell me________ ?
----Sorry, I don’t know.
A．where does he live
B．when will the film start
C．where is that new classmate from
D．who does the cleaning on Monday
