问题 选择题

下列命题中,为真命题的是(  )

A.对顶角相等

B.同位角相等

C.若a2=b2,则a=b

D.若a>b,则-2a>-2b

答案

A、对顶角相等为真命题;

B、两直线平行,同位角相等,故为假命题;

C、a2=b2,则a=±b,故为假命题;

D、若a>b,则-2a<-2b,故为假命题;

故选A.

材料分析题

马列杰迷上了上网,一回家就打开电脑上网,学习成绩下滑了许多。为此他的父亲禁止他上网,并把家里的电脑网线切断。马列杰对此很为恼火,并说:你不让我上网,我偏要上网,于是他用自己的零花钱到网吧上网。有一天,他到网吧上网的事情被母亲发现,母子俩人发生了激烈的争执。母亲说马列杰是朽木不可雕,马列杰说母亲是一个被时代淘汰的人……马列杰为此两个月不理母亲。阅读上述材料,回答下列问题:

(1)母亲不让马列杰上网,而马列杰偏要上网,这反映了马列杰一种怎样的心理?产生这种心理对他有什么危害?

                                                                                                                                                               

                                                                                                                                                              

                                                                                                                                                             

(2)马列杰在这件事上与他母亲意见不一致,你认为他应该怎么做?

                                                                                                                                                               

                                                                                                                                                              

                                                                                                                                                               

多项选择题