题目

The monkey was so lucky that it just missed ____．        A．catching                                    B．to be caught        C．being caught                                 D．to catch 答案：C写出下列命题的否定与否命题：（1）等腰三角形有两个内角相等．（2）可以被5整除的整数，末位是0．（3）若xy=0，则x=0或y=0．