问题 探究题

同学们共同研究滑轮的特点:

(1) 他们研究定滑轮特点时,做的实验如甲图所示,据此可证明:使用定滑轮                  .

(2) 他们研究动滑轮特点时,用动滑轮匀速竖直提升重物,如乙图所示.据此可知, 使用动滑轮                                                                     .

(3)他们组装了滑轮组,发现使用滑轮组提升重物时能省力,于是他们想:利用滑轮组提升重物能否省功呢?为此,他们进行的实验如丙图所示.请根据丙图信息.写出分析数据的具体过程,并回答他们的问题.

答案

(1)在改变动力方向时,不会改变拉力的大小;

(2)可以省力,但不能改变动力方向;

(3)W1=Gh=2×0.1=0.2J;

W2=Fs=0.8×0.3=0.24J;

[或

经比较W1< W2( 或η<1) ,所以使用滑轮组不能省功。

单项选择题

As any diplomat from Britain, Austria or Turkey can tell you, handling the legacy of a vanished, far-flung empire is a tricky business. But for Georgia, the gap between old glory and present vulnerability is especially wide.

Today’s Georgia is diminished by war, buffeted by geopolitics and recovering from post-Soviet chaos. But 800 years ago the country was a mighty military, cultural and ecclesiastical force. Its greatest monarch, Queen Tamara, defeated many foes (including her first husband) and built fine monuments. In her time, Georgia also had a big stake in the Christian life of the Holy Land. From Jerusalem to the Balkans, Georgia’s priests, artists and church-builders were active and respected. So too were its poets, like Shota Rustaveli, the national bard who dedicated an epic to his beloved queen.

In between seeking western aid and coping with power cuts, modern Georgia has pledged to keep a wary eye on every place where churches, inscriptions and frescoes testify to its golden age. That includes Greece, Turkey, Bulgaria, Romania and above all, Israel. Last year, Georgians were enraged when a fresco of Rustaveli, in a Jerusalem church under the care of the Greek Orthodox Patriarchate, was defaced, then badly restored. This year, a better restoration was done, but Georgians now want a promise that in all future restoration their own experts can take part. They also want to stop the seepage of Georgian frescoes and icons, supposedly under the Patriarchate’s care, on to the art market. Several times, Georgia has had to use its meagre resources to buy back pieces of the national heritage. The hope is that things will improve with the recent election of a new Jerusalem Patriarch, after his predecessor was ousted under a cloud of scandal.

Georgia’s ties with Israel are good, thanks to a thriving Georgian-Jewish community with happy memories of its homeland. Georgia also gets along with Greece, amid a fug of sentimentality over legends about the Argonauts that link the two nations. But can these warm, fuzzy feelings translate into better protection for an ancient culture That will be a challenge for Geld Bezhuashvili, who succeeds Salome Zourabichvili, the French-born diplomat who was sacked, after a power struggle, as Georgian foreign minister on October 19th.

Romania is mentioned in the text to ()

A. illustrate a fresco of Rustaveli

B. demonstrate the western aid Georgia obtained

C. indicate Georgia’s golden age

D.specify the scope of Georgia’s lookout

材料题

新中国成立以来,党和政府十分关注“三农”问题阅读材料回答问题:

材料一:土地改革的基本内容就是没收地主阶级的土地,分配给无地或少地的农民。这样,当做一个阶级来说,就在社会上废除了地主这一阶级,把封建剥削的土地所有制改变为农民的土地所有制。这种改革,诚然是中国历史上几千年来一次最大、最彻底的改革。——刘 * * 《关于土地改革问题的报告》

材料二:春联可以折射社会的风貌,1974年春联:过年只有两斤米,压岁并无一分钱。1980年春联:过年储米十余担,压岁存款上千元。

材料三:2010年1月31日,新华社播发了2010年中央一号文件,再度锁定“三农”。这份名为《中 * * 国务院关于加大统筹城乡发展力度进一步夯实农业农村发展基础的若干意见》的文件,是改革开放以来第12个以“三农”为主题的中央“一号文件”,围绕“稳粮保供给、增收惠民生、改革促统筹、强基增后劲”,对2010年农村工作进行了全面部署。2011年1月29日发布的《中 * *  国务院关于加快水利改革发展的决定》,是新世纪以来中央关注“三农”的第八个“一号文件”,也是新中国成立62年来中央文件首次对水利工作进行全面部署。

(1)材料一中刘 * * 说土地改革是“中国历史上几千年来一次最大、最彻底的改革”的依据是什么?

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(2)结合材料二,依据所学知识回答:在这段时间内,什么原因使中国农民出现如此大的改变?

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(3)党和政府重视“三农”问题,总在不断地调整农村政策。你认为在制定农村政策时要注意些什么?

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