52－7=____
35－8=____
73－9=____
64－8=____
Anyone who has spent time with children is________of the difference in the way boys and girls respond to similar situations.
李嘉图关于工资和利润关系的观点有（ ）
①工资上升，利润上升 ②工资下降，利润下降
③工资上升，利润下降 ④工资下降，利润上升
