单项选择题
A.类 B.属性 C.对象 D.消息
A.p={HK,HI,IJ,JKL,HL} B.P={HIL,IKL,IJL} C.P={HJ,IK,HL} D.P={HI,JK,HL}
A.vulnerable B.week C.sensitively D.helpless