如图是三种脊椎动物形态结构示意图,请据图回答:
把3米长的绳子平均分成5份,1份是 15 米.
不等式组y≥0y≥x-2y≤x所围成的封闭图形的面积为( )
—This apple pie is too sweet, don't you think so?
—_____. I think it's just right, actually.