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1．一本物理课本的质量约为············································································· ( )
A．10克 B．100克 C．500克 D．2000克
2．调节收音机的音量，是为了改变声音的························································ ( )
A．音调 B．频率 C．音色 D．响度
3．物质的分子具有分子动能是由于··································································· ( )
A．分子之间有间隙 B．分子不停地做无规则运动
C．分子之间有相互作用的引力 D．分子之间有相互作用的斥力
4．光垂直入射到平面镜上，反射角为······························································· ( )
A．0° B．30° C．45° D．90°
5．能体现物质特性的物理量是·········································································· ( )
A．质量 B．电阻 C．密度 D．速度
