设向量函数A(t)={2cost,sint,t},则导数向量为()。 A.{-2si

题型:单项选择题

问题:

设向量函数A(t)={2cost,sint,t},则导数向量为()。

A.{-2sint,cost,1}

B.{2sint,cost,1}

C.{-2sint,sint,1}

D.{-2cost,sint,1}

考点:一级注册结构工程师一级结构师基础知识一级注册结构工程师基础知识考前冲刺(二)
题型:单项选择题

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      "Grandma, Grandma, tell us a story!" Four darling children sat by my feet, looking up at me

expectantly.

     Suddenly, we were interrupted clapping. "Terrific," the director said, stepping up the stage from

the aisle(过道). "Except, could you kids face the audience a bit more?"

     The kids shifted to face the empty seats, which would be filled in a few days for the church play.

"Perfect," the director said. "Now, Grandma, read to your grandchildren." A pang of sadness hit me.

If only I could read to my real grandchild!

     I had a granddaughter, but I'd never met her. Sixteen years earlier my son was involved in a

relationship that ended badly. But out of it came a blessing: a baby girl named Lena. I hoped to be a

grandmother to her-but shortly after the birth, the mother moved without any address left. Over the

years, I asked around town to try and find my son's exwife(前妻), but it seemed that she didn't want

to be found.

     I 'd just joined this new church a week earlier, and was at once offered the part of Grandma in the

play.  At least now I could pretend to be a grandma. The rehearsals went well, and finally the day of

the show arrived. The performance was great. "You all looked so natural up there," one of my friends

said.

     Afterward, we went to the church basement for refreshments(茶点). I walked over to one of the

girls in the play, Rehearsals had been such a whirlwind(一片忙乱) that we never really got to talk.

"How's my granddaughter?" I joked.

     "Fine!" she answered. Just then, someone else walked up and asked the girl her name.

     I wasn't sure I heard the girl's answer correctly. But it made me ask her another question. "What's

your mother's name?"

    She told me, I was still in shock. "And what's your father's name?" I asked. She told me. It was my

son.

    She'd only started going to that church a week before I did. Since that day of the play, we've stayed

close. Not long ago, she even made me a great grandma.

1. What was the author doing at the beginning of the story?

A. Telling a story.  

B. Playing a game.

C. Preparing for a play.  

D. Acting in a movie.

2. Why did the author feel "A pang of sadness" at the words of the director?

A. The director's words reminded her of her lost granddaughter.

B. The director's words hurt her so badly.

C. She wished that she had a real grandchild.

D. The director wasn't content with her performance.

3.We can infer that when writing the story, the author felt ________.

A. lighthearted  

B. heartbroken

C. confused  

D. anxious

题型:单项选择题

轴承保持架可以避免滚动体之间由于()而增大摩擦阻力和磨损。

A、接触

B、直接接触

C、窜动

D、撞击

题型:单项选择题

男,45岁,发现有动脉硬化症状。查体:见角膜有老年性色素环。查血:TC12.00mmol/L,TG2.6mmol/L。

最可能的诊断是()

A.混合性高脂血症

B.高甘油三酯血症

C.家族性高胆固醇血症

D.Ⅰ型高脂血症

E.Ⅱ型高脂血症

题型:单项选择题

()被认为是国内仅见的、目前保存最完整的道教遗址。

A.华清宫老君殿遗址

B.鹿邑太清宫遗址

C.龙兴观遗址

D.芮城五龙庙

题型:单项选择题

在DISCOvery过程中ONU如果所收到的消息类型为DISCOvery,且消息中的逻辑PHYID与自己相同或为缺省值是,就不对此消息做出应答。

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