A:一切从实际出发,实事求是
B:集中主要力量解决主要矛盾
C:善于分清主流和支流
D:人民群众是社会历史的主体
When will the boy's friends get to the station?
设变量x,y满足x+y≤1x-y≤1x≥0,则目标函数x+2y的最大值和最小值分别为( )
--A latest English newspaper, please!--Only one copy left. Would you like to have __________, sir?