已知m，n是两条不同直线，α，β是两个不同平面下列命题中不正确_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题选择题

已知m，n是两条不同直线，α，β是两个不同平面下列命题中不正确的是（　　）

A．若m∥α，α∩β=n，则m∥n

B．若m∥n，m⊥α，则n⊥α

C．若m⊥α，m⊥β，则α∥β

D．若m⊥α，m⊂β，则α⊥β

答案

A选项不正确，因为由线面平行的性质定理知，线平行于面，过线的面与已知面相交，则交线与已知线平行，由于m与β的位置关系不确定，故不能得出线线平行；

B选项正确，因为两条平行线中的一条垂直于某个平面，则另一条必垂直于这个平面；

C选项正确，两个平面垂直于同一条直线，则此两平面必平行；

D选项正确，一个平面过另一个平面的垂线，则这两个平面垂直．

综上，A选项不正确

故选A

单项选择题

某单位的百兆以太网信号类型为基带，电缆类型为非屏蔽超五类双绞线，电缆连接器类型为RJ-45。该单位需将其升级为千兆以太网，则升级为（）网络的成本最低。

A.1000BaseTCX

B.1000BaseT

C.1000BaseSX

D.1000BaseLX

完形填空

My mother let go of me when I could not let go of her .In one last brave moment she was strong for me ,thus making me strong ,too.
I was in the kitchen when        called and told me to make a quick decision .They could only hold a place for my         until the next morning.
The thought of being        from my Alzheimer’s stricken (早老性痴呆)mother when she needed me most       me .Dad died when I was a teenager ,Mom and I had        many hard times together .Mom taught me to laugh my way through bad experiences and sing through     days .But in recent years , except for extremely        moments of consciousness , she’d become lost in her own private world .I knew that Mom needed       nursing and medical care ,yet the possibility of a complete stranger coming to her at night ,when she would      around like a sleepwalking child ,filled me with a feeling of      .
Two bitter days passed     we left for the nursing home .I hugged and kissed her with       tears ,I’d always planned the best golden years for Mom in her old age ,but now I was saying    .
Suddenly there was something shining in her     , a look of recognition .“Stop crying now”,she said firmly ,“Say goodbye and get going .Don’t     about me .”
I stood with     and stared into her face .“Mom!”I cried and reached out for her .But as quickly as my “real ”Mom had appeared ,she    again into her world of a little child .       ,at that very moment I realized the mother ,that familiar Mom who knew and understood ,who      and sang with me in hard times ,would always be there , giving me       when I needed it most .

A．the hospital

B．the nursing home

C．the kindergarten

A．unforgettable

B．comfortable

C．professional

A．satisfaction

B．disappointment

D．recognition

A．disappeared