我国历史上规模最大的长城是( )。
A．秦长城B．楚长城C．汉长城D．明长城
参考答案：C
一位古希腊人经过实地调查研究，在其著作中记述了希波战争的始末。他是[ ]
A．伯里克利
B．希罗多德
C．柏拉图
D．罗马
As far as we know, half of Canadian teenagers do not get enough sleep on school nights, _____?[ ]
A. do they
B. don't they
C. don't you
D. isn't it
