A:甲厂生产的皮鞋价值量大
B:乙厂生产的皮鞋价值量大
C:丙厂生产的皮鞋价值量大
D:甲乙丙三厂生产的皮鞋价值量一样大
设x,y满足2x+y≥4x-2y≤2x-y≥1则z=x+y( )
Dutch tulips in Dafeng are so charming that _________ tourists go there and enjoy the beautiful flowers every day.