题干

如图所示,已知半径分别为R和r(R>r)的甲、乙两个光滑的圆形轨道安置在同一竖直平面上,甲轨道左侧又连接一个光滑的轨道,两圆形轨道之间由一条水平轨道CD相连.一小球自某一高度由静止滑下,先滑上甲轨道,通过动摩擦因数为μ的CD段,又滑上乙轨道,最后离开圆轨道.若小球在两圆轨道的最高点对轨道压力都恰好为零.试求:

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任务型阅读

    Do you like reading? How often do you go to a bookshop? To compete with online sellers, traditional bookshops have tried everything to win customers. And it is true that a great bookstore can encourage people to read in many ways. Here are some good shops in China and other countries that are worth a visit.

Eslite Bookstore, Suzhou

    The Eslite Bookstore is very popular among young people in Suzhou. It has fashion shops, cafes and other places. It also holds many reading-relative activities including discussions and talks with famous writers.

Sanlian Taofen Bookstore, Beijing

    It is 11:30 pm. But the Sanlian Taofen Bookstore is shining brightly. Many people are staying inside for one thing: to read. The bookstore is open 24 hours a day. It's the first bookstore of its kind in Beijing.

Shakespeare & Company, France

    France doesn't have Shakespeare but it has Shakespeare & Company. Many great writers used to meet here including Ernest Hemingway. Today, it helps young writers by allowing them to live and work here.

Strand Bookstore, US

    Strand Bookstore is a second-hand bookstore. It sells books for $2-3 each, much cheaper than they used to be. Sometimes you can even find very old and rare books here. For example, a Shakespeare book that was published in 1632 is worth $125,000!

阅读以上信息,用恰当的词完成下面的表格,每空一词。

Good bookstores that are worth ____

Eslite Bookstore, Suzhou

·Many young people like it because it is fashionable.

·Readers can also ____ the books here and have talks with famous writers.

Sanlian Taofen Bookstore, Beijing

·People can read here as ____ as they want because it is never closed.

Shakespeare Company, France

·Many great writers used to meet here.

·Young writers are ____ to live and work here.

Shakespeare & Company, France

·You can buy books at a ____ price because they are used.

·You can even find old and rare books which are very valuable.