__________ the assignment made his father lose his temper.

A．The boy’s not having done

B．The boy not having done

C．The boy’s having not done

D．The boy having not done

故障模式是指故障的表现形式，下列属于损坏型故障的是（）

A、断裂、碎裂、开裂、点蚀、烧蚀、变形

B、老化，变质、剥落、异常磨损

C、松动、脱落

D、压力过高或过低、性能衰退、公害超标