The man, ____ legs were badly hurt by a ______worker, was____to hospital at once.

A．whose; careless; taken

B．his; careless; sent

C．whose; carelessly; sent

D．his; carelessly; taken

在车床上加工心轴，见图2—11后，经检验发现A有圆柱度误差，B对A有垂直度误差。试从机床几何误差的影响，分析产生上述误差的原因。