教室中未搬入桌凳前说话常有嗡嗡的尾声,摆了桌凳坐满了学生后这种现象减轻到似乎听不到了,这是因为____.
东西半球的分界线是( )
解不等式组:5x+1>3(x-1)12x-1≤7-32x.
小光同学捡到了价值400元的手机,当失主索要时他拒不归还。小光同学的这一行为( )
Today is Wednesday. What day is it tomorrow?