A:圆锥
B:圆柱
C:正三棱柱
D:正三棱锥
一个球,圆溜溜,雨天无,晴天有。早从东方起,晚在西山落。____
—It's said the Nanjing Airport light rail_________ into service in two months.— That's great! It will be fast to go to the airport.
如果不等式组x>ax<b无解,那么不等式组的解集是( )