问题 问答题

甲、乙两物体的质量之比是10﹕7,已知甲物体重为5N,则乙物体重为多少?能否用最大称量是500g的天平称出乙物体的质量?

答案

∵G=mg,

∴G:G=mg:mg=m:m=10:7,

∵G=5N,

∴G=3.5N,

m=

G
g
=
3.5N
9.8N/kg
≈0.38kg<500g,

∴能用最大称量是500g的天平称出乙物体的质量.

答:乙物体重为3.5N,能用最大称量是500g的天平称出乙物体的质量.

材料题

阅读下列材料,回答问题。

材料一 电报作为近代科技发展的产物,真正进入中国人的视野是在第二次鸦片战争之后。当时,列强为了利用电报这种全新的通讯工具,提高政令军情传达的速度和效率,加强对中国的侵略、控制,提出了在中国铺设电线的要求,但遭到清廷婉拒。1874年,日本发动侵台战争。清廷看到了通讯工具落后、消息闭塞的害处,朝野上下对电线铺设与否展开争论。而此时列强加快了使电报进入中国的进程。1871年;英国人悍然在香港与上海之间铺设了电线。 * * 衙门对既成事实消极应对,允准铺设水线,仍禁止铺设陆线。李鸿章则主张,既然抵挡不住洋人,不如立足现实,自行铺设电线、举办电报事业。1877年,直隶总督李鸿章最终主持自行铺设了从天津机器东局至直隶总督衙署的电线,随后命于大沽、北塘炮台铺设直达天津电线,并号令淮军各营,顷刻响应。自此,近代中国的电报业发展起来。

材料二 1949年以后,中央人民政府加大投入迅速恢复和发展通信。1958年建起来的北京电报大楼成为新中国通讯发展史的一个重要里程碑。国内最早研制投产的电传机当数1955年问世的55型电传机,此后,国产电报机研发技术不断进步,60年代,“中文电报译码机”问世,可以自动把电码译成汉字,其译印速度相当惊人,每分钟高达2800个汉字,平均速度为每分钟1500个汉字。国产电报机逐渐成为内地市场的主流并组成了国内较为庞大的电报通信网,到1987年,我国已有65个城市开放了用户电报业务,初步形成了以北京上海为国际业务终端局、以省会城市为骨干的国内、国际用户电报网络体系。

材料三 2001年8月1日,从那天起,中国电信集团公司取消公众电报业务中的特急和加急业务。此举预示传统电报业务正在淡出百姓的生活,北京电报大楼几乎成为一个时代的象征,而今天,这座著名的电报大楼里的电报业务柜台“蜷缩”在一个很不显眼的地方,每天打电报的用户也只有几位。

(1)根据材料一,指出清廷对电报的态度经历了怎样的变化历程,并分析其发生变化的原因。

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(2)根据材料二并结合所学知识,分析我国电报业在建国后至改革开放初期得以快速发展的原因。

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(3)材料三反映了什么现象?简析其主要原因。

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单项选择题

Walking through my train yesterday, staggering from my seat to the buffet and back, I counted five people reading Harry Potter novels. Not children-these were real grown-ups reading children’s books,
Maybe that would have been understandable. If these people had jumped whole-heartedly into a second childhood it would have made more sense. But they were card-carrying grown-ups with laptops and spreadsheets returning from sales meetings and seminars. Yet they chose to read a children’s book.
I don’t imagine you’ll find this headcount exceptional. You can no longer get on the London Tube and not see a Harry Potter book. Nor is it just the film; these throwback readers were out there in droves long before the movie campaign opened.
So who are these adult readers who have made JK Rowling the second-biggest female earner in Britain (after Madonna) As I have tramped along streets knee-deep in Harry Potter paperbacks, I’ve mentally slotted them into three groups.
First come the Never-Readers, whom Harry has enticed into opening a book. Is this a bad thing Probably not. Writing has many advantages over film, but it can never compete with its magnetic punch. If these books can re-establish the novel as a thrilling experience for some people, then this can only be for the better. If it takes obsession-level hype to lure them into a bookshop. that’s fine by me. But will they go on to read anything else Again, we can only hope.
The second group are the Occasional Readers. These people claim that tiredness, work and children allow them to read only a few books a year. Yet now—to be part of the crowd, to say they’ve read it—they put Harry Potter on their oh-so-select reading list. It’s infuriating, and maddening. Yes, I’m a writer myself, currently writing difficult, unreadable, hopefully unsettling novels, but there are so many other good books out there, so much rewarding, enlightening, enlarging works of fiction for adults; and yet these sad cases are swept along by the hype, the faddism, into reading a children’s book.
The third group are the Regular Readers, for whom Harry is sandwiched between McEwan (英国当代作家) and Balzac, Roth (德国现代诗人) and Dickens. This is the real baffler—what on earth do they get out of reading it Why bother But if they call rattle through it in a week just to say they ve been there—like going to Longleat (朗利特山庄英国名胜) or the Eiffel Tower—the worst they’re doing is encouraging others.

According to the author, the Never-Readers ______.

A.will take up reading as their lifelong hobby

B.have got more from the book than from the film

C.may barely get interested in other books than Harry Potter

D.can hardly be driven by the crowds to read any book