车床床身的毛坯大都是()而成。 A.铸造 B.锻造 C.焊接 D.切削加工

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问题:

车床床身的毛坯大都是()而成。

A.铸造

B.锻造

C.焊接

D.切削加工

考点:机电设备评估基础第二章机器设备设计制造基础第二章机器设备设计制造基础题库
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如图所示,质量为m的木块P在质量为M的长木板ab上滑行,长木板放在水平地面上一直处于静止状态.若长木板ab与地面间的动摩擦因数为μ1,木块P与长木板ab间的动摩擦因数为μ2,则长木板ab受到地面的摩擦力大小为(  )

A.μ1Mg

B.μ1(m+M)g

C.μ2mg

D.μ1Mg+μ2mg

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出口食品卫生注册证书的有效期为3年。( )

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For years I fought with the bird's nest that sat on top of my head-my Medusa(神话中的蛇发女妖) hair.No matter what I did and how hard I tried, in no way could I make my unruly (乱蓬蓬)hair to my satisfaction.

Growing up in a Russian-Jewish home with parents who thought North American styling products  were something illegal such as drugs, I was never allowed to put them in :my hair.¨ Why buy hair gel? Your hair is so beautiful naturally," my mother would say.The teens at school did not agree.From boys 'not wanting to kiss me when we played spin the bottle in Grade 7 to being called the mop, I suffered from my hair.

When I got to university, I believed my hair was a wall that stood between me and everything-finding a part-time job, getting a boyfriend, etc.

If only I could find a way to manage the curls and put it behind bars, I told myself, I would feel secure and sexy.I tried everything: rollers, hairspray, gels and, at one point, an iron.Then, in my second year, a miracle happened.I was asked to be a hair model for Japanese hair straightening, a process by which the molecules(分子)of my curls would be broken and reset in a bone-straight position.I was the perfect candidate, the hairdresser told me. Although they said how hair relaxing could damage the :scalp (头皮),for the next five years I didn't find them to be true. All of the hairdresser's promises were fulfilled:  With my hair straight and smooth, I was no longer the¨ mop".

However, there was extreme damage done to my wallet. To keep up the straightening cost  $ 700 every six months, and that was considered cheap.While some people thought I was crazy, I was willing to do anything to never again feel like that anxious, curly-headed girl in Grade 7.But when I moved out. of my parents" house 'at age 26 and rented an apartment, the upkeep of my new image became too costly.

I couldn't hide from my inner Medusa any longer.It was time to hug her and let her fly.Seeking a choice, I turned to the Internet, Google.After hours of searching, I hit upon a“ curly haired"  salon, a place designed for girls like me.I doubted these so-called “Curl Ambassadors" could do anything

without using machine of some sort, and though I bought the service called the “Curly-Doo,"  I suspected I'd have the same unruly mop at the end of the appointment.

I dragged my feet so hard getting there that I arrived 45 minutes late. I secretly hoped they would turn me away.Instead, my stylist simply said :‘‘You are very late. Let me see your hair" At. that moment, my world and beliefs about myself were turned upside down along with my hair. As my head was in a basin full of freezing-cold water, then covered with a jelly-like jam, I wondered what I had got myself into.

¨ Do you really think this will work?"  I asked the stylist, Jones.“ My curls are a disaster."“No curly hair is hopeless," she replied.“They just haven't found a way to work with it, that's all. "

After the hour was over, Jones had completed her work. She had styled my hair using only her hands, water and a mixture of organic jam. I couldn't believe what I was seeing in the mirror: a naturally curly, Medusa-free me.You could argue that hair is just hair. Yet, it is just such physical features that have such a large influence on how we view ourselves.

According to Jones,75 percent of the population have a wave or curl in their hair and don't know what to do with it. Men cut theirs short. Women flat-iron theirs to death. When I read through a beauty magazine or take the subway to work, it makes me sad to see so many people repressing their natural beauty.

Since then, my world has changed. I have always been outgoing, but these days I seem to be more outspoken and confident than ever. On top of that, friends and co-workers tell me I am looking better than ever, but they don't know the source of the change.

I don't need to tell them* My Medusa hair speaks for herself.

小题1:What can we learn about the writer's hair in the first place?

A.Her parents considered it was bird's nest.

B.Teens at school laughed at it as Medusa hair.

C.She hated it because it couldn't be straightened.

D.North American styling products harmed her hair.小题2:Japanese hair straightening caused a problem for the writer that        

A.her wish to feel secure and sexy didn't come true

B.her hair was seriously damaged after the straightening

C.the cost to keep her hair straight was too high for her

D.she was called ¨the mop" with her hair straight and smooth小题3:The writer was        when she went to the “curly haired" salon.

A.hesitated

B.excited

C.disappointed

D.determined小题4:What was the reaction of the stylist in the salon when she saw the writer?

A.She was very angry because the writer was late.

B.She thought totally the writer's hair was a disaster.

C.She was calm and sure of her work.

D.She thought there was no way to fix the writer's hair.小题5:The writer's world has changed because she      

A.has removed her inner Medusa

B.has removed her curls on her head

C.has found a way to straighten her hair in the stylish salon

D.has found the admiration for her from her friends and co-workers小题6:The best title of the passage can be     

A.A Successful Stylist

B.My Medusa Hair

C.Road to Beauty

D.Accept the Way We Are

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关于唾液腺的排泄管的叙述正确的是( )

A.是导管最细小的终末分支部分

B.穿行于小叶间结缔组织中

C.管壁由单层柱状上皮所组成

D.连接腺泡与分泌管

E.以上均不正确

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血海与冲门的连线上,血海穴上6寸取()

A.关门

B.箕门

C.大横

D.气冲

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