问题 填空题

托盘天平主要由六部分构成:分度盘、指针、托盘、平衡螺母、游码、标尺.托盘天平只能精确到______,使用时要做到“一调、二放、三要”.

一调:称量前把游码放在标尺的______处,通过调节______来调节天平平衡.

二放:干燥的固体药品放在纸上称量(应在两个托盘上各放一张质量相同的纸);易潮解、有腐蚀性的药品应放在______中称量.

三要:要“______物______码”;要“先大后小”,即先加质量大的砝码后加质量小的砝码,最后移动游码;要用______夹取砝码,不能用______去拿取砝码.

答案

天平能准确到0.1g,在称量前游码必须拨到零刻度处,调节天平平衡时要通过调节平衡螺母来调节,易潮解、有腐蚀性的药品不能直接放在托盘上,要放在玻璃器皿中称量,左盘放药品,右盘放砝码,在使用砝码时要用镊子夹取,不能用手拿,防止手上的汗液沾附在砝码上,使砝码生锈.

故答案为:0.1g;零刻度;平衡螺母;玻璃器皿;左;右;镊子;手.

阅读理解

Having finished her homework,Ma Li wants some music for relaxation(娱乐).As usual,she starts her computer and goes to Baidu.Come to download music files.But this time she is surprised when an announcement about protecting songs'copyright bursts onto the screen.The age of free music and movie downloads may have come to an end as Web companies like Baidu are accused of pirating copyright.Lawsuits(诉讼)have been filed against four websites offering free downloads.In September 2005, a Beijing court ordered Baidu to pay recording company Shanghai Push compensation(赔偿)for their losses.Baidu was also told to block the links to the pirated music on the website.This caused a heated discussion on Internet file sharing.

“Baidu's defeat in the lawsuit shows it is not right to get copyrighted songs without paying.Downloaders may face lawsuits or fines,”said an official.

Like many teens,Huang Ruoru,an 18­year­old girl from Puning in Guangdong Province,doesn't think that getting music from websites is wrong.She always shares her favourite songs downloaded from Baidu with her friends.When told about the lawsuit,she began to feel a little guilty about obtaining others' work without paying.

However,other teenagers have different ideas.Wang Yafei,a Senior 2 girl from Jinan,Shandong Province pointed out that file sharing is a good way to promote pop singers.“If I download a song and really like it,I will buy the CD,”she said.“So what the recording companies really should concentrate on is improving their music,rather than pursuing(追赶,追击)file­sharers.”

小题1:Which of the following best describes the passage?

A.Music on the Internet is of better quality.

B.Downloading material can be illegal.

C.It's good to get free music on the Internet.

D.Baidu is a popular Web company.小题2:The four Web companies were put to court because ________.

A.they got copyrighted songs without paying

B.they downloaded copyrighted music for people

C.they make copyrighted files for free downloads

D.they offer free music on line小题3:How do some of the teenagers feel while downloading free music after the lawsuits?

A.A bit guilty.

B.A little sad.

C.Extremely angry.

D.Awfully sorry.

单项选择题