试题与答案

小明是九年级学生,在一次化学实验中,要用托盘天平称取一定质量的药品.他知道,为保

题型:问答题

题目:

小明是九年级学生,在一次化学实验中,要用托盘天平称取一定质量的药品.他知道,为保护天平,化学药品不能直接放到天平盘上,要在放药品的盘中垫一张纸片.关于测量前的调节,小明同学考虑了下列一些方案,你认为最合理的是(  )

A.先调节平衡螺母使天平平衡,然后在两个盘中各放一张相同的纸,再进行药品质量的测量

B.先调节平衡螺母使天平平衡,然后在左盘中放一张纸,再调节游码使天平重新平衡,接着进行药品质量的测量

C.先调节平衡螺母使天平平衡,然后在左盘中放一张纸,再调节平衡螺母使天平重新平衡,接着进行药品质量的测量

D.先在左盘中放一张纸,然后调节平衡螺母使天平平衡,接着进行药品质量的测量

答案:

A、托盘天平已经调平,再在左右盘中,各放一张大小相同质量相等的纸,由于两张纸的质量完全相等,所以放上纸后,天平会仍然平衡.这样就排除了纸张对实验的影响,可以再纸上放置化学药品进行称量.故A正确.

B、盘天平的使用实际就是包括两次横梁平衡的调节,第一步通过调节平衡螺母使横梁平衡,第二步通过加减砝码,移动游码来使横梁平衡.此时还属于第一次横梁平衡的调节,要将游码放在标尺左端的零刻度线处,不能移动游码的位置,只有在放上被测量的物体后,才能移动游码使横梁平衡.故B错误.

C、第一次调节横梁平衡,没有效果,因为放上纸片后,横梁又失去了平衡,还需要重新调节,因此可以把第一次的调节去掉.故C错误.

D、由于放在天平左盘中的这张纸的影响,再调节天平横梁平衡时,会出现平衡螺母不能使天平横梁平衡的现象.故D错误.

故选A.

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题型:阅读理解

Flowers only bloom(开花) when they are planted in the right soil. That is also true for me.

I first moved to Foxboro, Massachusetts, as a single mother with my baby daughter, Darcy. I was drawn to its New England beauty, friendly people and rich history. It happened that there were a lot of forsythia(连翘) bushes around the house in which I lived just like my childhood home. I joined St. Mark’s Episcopal Church where I taught the Sunday school. At church, I met my second husband, Dean. For more than 25 years, I bloomed in Foxboro, and I had another two children.

Then, when Darcy was a few years out of college, she moved to Alameda, California, to be near friends. I missed her badly. A year later my beloved husband Dean had deadly cancer. He only made it eight months. My heart was broken. Later I moved to Alameda with my children. It was a beautiful Victorian island, and I was grateful to spend more time with Darcy. I even attended a church and made a few friends there. Still, I couldn’t help but miss Foxboro. It had everything and everyone I loved.

One spring day, when I was walking by a school, something yellow caught my eyes. Forsythia bushes! They made me homesick and I kept back my tears. “I miss you, Foxboro,” I whispered. Then I went into a shop and looked at some ceramic(陶瓷的) pots lined up on a shelf. A large white one seemed to catch my attention. “That’ll be perfect in my living room,” I thought.

I turned it over to look at the price. Instead I found these words: “New England Pottery, Foxboro, Massachusetts.” A piece of artwork, from my second hometown, was right here. It was able to spread across the country and so were forsythia bushes. I took it as a sign that I can bloom, right where I am.

小题1:From the text we learn that the author ____.

A.gave birth to three children in Foxboro

B.planted forsythia bushes around her house

C.got to know her second husband at church

D.worked as a middle school teacher in Foxboro小题2:The author moved to Alameda so that she could ____.

A.have more time together with Darcy

B.forget the sorrow at her husband’s death

C.visit her children at Alameda College frequently

D.enjoy the beautiful scenery on the Victorian island小题3:When the author saw forsythia bushes at a school she _____.

A.wanted to buy a ceramic pot to put them in

B.thought of her life in Foxboro

C.felt they would look great in her living room

D.believed they were real art work小题4:Why does the author compare herself to flowers?

A.Because she wanted to show she likes flowers.

B.Because she can live in any place that is right like flowers.

C.Because she moved across the country just like flowers.

D.Because girls are like flowers that are blooming.

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