题目内容

一质点做匀速直线运动,现对其施加一恒力,且原来作用在质点上的力不发生改变,则()。

A. 质点速度的方向总是与该恒力的方向相同
B. 质点速度的方向不可能总是与该恒力的方向垂直
C. 质点加速度的方向总是与该恒力的方向相同
D. 质点单位时间内速率的变化量总是不变

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下列实验操作能达到实验目的的是()。

A. 用长颈漏斗分离出乙酸与乙醇反应的产物
B. 用向上排空气法收集铜粉与稀硝酸反应产生的NO
C. 配制氯化铁溶液时,将氯化铁溶解在较浓的盐酸中再加水稀释
D. 将Cl2与HCl混合气体通过饱和食盐水可得到纯净的Cl2

George()too far . His coffee is still warm.

A. must have gone
B. might have gone
C. can't have gone
D. needn't have gone

DTwo things changed my life: my mother and a white plastic bike basket. I have thought long and hard about it and it’s true. I would be a different person if my mom hadn’t turned a silly bicycle accessory into a life lesson I carry with me today.My mother and father were united in their way of raising children, but it mostly fell to my mother to actually carry it out. Looking back, I honestly don’t know how she did it. Managing the family budget must have been a very hard task., but she made it look effortless. If we complained about not having what another kid did, we’d hear something like, “I don’t care what so –and –so got for his birthday, you are not getting a TV in your room a car for your birthday a lsvish sweet 16 party.” We had to earn our allowance by doing chores around the house. I can stil l remember how long it took to polish the legs of our coffee table.My brothers can no doubt remember hours spent cleaning the house .Like the two little girls growing up at the White House,we made our own beds (no one left the house unitil that was done)and picked up after ourselves.We had to keep track of our belongings ,and if something was lost ,it was not replaced. It was summer and ,one day ,my mother drove me to the bike shop to get a tire fixed---and there it was in the window, White, shiny, plastic and decorated with flowers ,the basket winked at me and I knew ----I knew---I had to have it. “It’s beautiful,” my mother said when I pointed it out to her,”What a neat basket.”I tried to hold off at first ,I played it cool for a short while.But then Iguess I couldn’t atand it any longer:“Mon, please can I please ,please get it? I ‘ll do extra chores for as long as you say, I’ll do anything ,but I need that basket,I love that basket.Please ,Mom .Please?”I was desperate.“You know,” she said ,gently rubbing my back while we both stared at what I believes was the coolest thing ever,”If you save up you could buy this yourself.”“By the time I make enough it’ll bu gone!”“Maybe Roger here could hold it for you,” she smiled at Roger ,the bike guy.“He can’t hold it for that long ,Mom .Someone else will buy it .Please,Mom,Please?”“There might be another way,”she said.And so our paying plan unfolded.My mother bought the beautiful basket and put it safely in some hiding place I could’t find.Each week I eagerly counted my growing saving increased by extra work here and there (washing the car ,helping my mother make dinner, delivering or collevting things on my bike that already looked naked without the basket in front).And then ,weeks later ,I counted ,re-counted and jumped for joy. Oh ,happy day ! I made it! I finally had the exact amount we’d agreed upon….Days later the unthinkable happened. A neighborhood girl I’d played with millions of times appeared with the exact same basket fixted to her shiny ,new bike that already had all the bells and whistles. I rode hard and fast home to tell my mother about this disaster.This horrible turn of events.And then came the lesson . I’ve taken with me through my life:”Honey, Your basket is extra-special,” Mom said, gently wiping away my hot tears.”Your basket is special because you paid for it yourself.” By using“naked” (Paragraph 12),the author seems to stress that the basket was()

A. something she could afford
B. something important to her
C. something impossible to get
D. something she could do without

When I was a very young children,my father created a regular practice I remember well years late.Every time he arrived home at end of the day ,we’d greet het at the door.He would ask who we was and pretend not to knowing us,Then he and my mother would have had a drink while she prepared dinner and they would talk about his day and hers.While they chat,my father would lift my sister and me up to sit in the top of the fridge.It was both excited and frightening to be up there!My sister and I thought he was so cool for putting us there. 9()

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