问题 解答题

某人用一架不等臂天平称一铁块G的质量,当把铁块放在天平的左盘中时,称得它的质量为0.4千克;当把铁块放在天平的右盘中时,称得它的质量为0.9千克,求这一铁块的实际质量.

答案

设不等臂天平的左,右臂的长分别为l1,l2,铁块的实际质量为m千克,

由题意得

ml1=0.4l2
ml2=0.9l1

①×②得m2l1l2=0.36l1l2

即m2=0.36,

∴m=0.6.

答:铁块的实际质量为0.6千克.

阅读理解

Hi, everybody!

Welcome to our newly-opened Richards Cinema Bookstore!

Now let me introduce to you some of the new film books in our store.

Are you Chinese film fans? OK, here comes the latest 25 New Takes about Chinese films. It is a collection of 25 fresh readings of different Chinese films from the 1930s to the present. In recent years, Chinese films are very popular in the States, such as Crouching Tiger and Hidden Dragon, Hero, and Flowers of Shanghai.

Do you like French films? Well, here is The French Cinema Book. It covers French films from the 1890s to the beginning of the 21st century. It is written for all lovers of French cinema: students and teachers, specialists and fans, and so on.

Maybe you are Indian film fans and star-chasers. Then here is Encyclopedia (百科全书) of Indian Cinema. The book is a complete introduction to all the best Indian films. It also offers a full list of names of the famous and successful film stars in the past ten years. You know, the Indian film industry is the largest in the world after our Hollywood.

If you like British films, we have The British Cinema Book. It is a good review of British cinema. This book contains a good many nice pictures.

In our bookstore, you can also find books about Mexican, Japanese, Australian, German and Italian films.

Well, please help yourselves to some coffee or tea, and have a good time here!

小题1:The speaker of the passage is most probably _______.

A.the writer of 25 New Takes

B.a tourist in the cinema bookstore

C.the manager of the cinema bookstore

D.a reader of Encyclopedia of Indian Cinema小题2:How many Asian countries does the speaker refer to when he talks about the film books?

A.Two.

B.Three.

C.Four.

D.Nine.小题3:Which of the following statements is NOT mentioned in the passage?

A.Indian cinema is second only to Hollywood.

B.The British Cinema Book includes a complete list of names of stars.

C.Crouching Tiger and Hidden Dragon is well received in the States.

D.The French Cinema Book covers over a century's French films.小题4:The purpose of the speaker is_______.

A.to satisfy the visitors' various tastes

B.to keep the writers in the cinema bookstore

C.to offer the visitors chances to meet the film stars

D.to have the readers into film producers

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