如图所示为推行节水灌溉工程中使用的转动式喷水龙头的示意图．喷水口离地面的高度为5m，用效率为50%的抽水机从地下20m深的井里抽水，使水充满水口并以恒定的速率从该水龙头沿水平喷出．喷水口横截面积为10cm²，其喷灌半径为10m，若水的密度为1×10³ kg/m³，不计空气阻力．带动该水泵的电动机的最小功率为（取g=10m/s²）（　　）

A．9×10³W

B．6×10³W

C．4.5×10³W

D．3×10³W

Not only _______interested in Beijing Opera but ______beginning to show an interest in it.

A．the father himself is; all his children are

B．the father himself is; are all his children

C．is the father himself; are all his children

D．is the father himself; all his children are