生矿中最易还原的是（）。
A．硫铁矿
B．赤铁矿
C．褐铁矿
D．菱铁矿
参考答案：C
The World Cup has been the ______ of this month's events; a large number of soccer fans around the world focus their attention on the little "ball".
A．twilight
B．realms
C．highlights
D．headlines
民主首先是 ( )
A．一种国家制度B．人民的自由C．阶级斗争的工具D．人类追求的目标
