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百育二中化学兴趣活动小组的同学用洁净的塑料瓶从右江河中取回一定量的水样，然后进行如下研究分析：

（1）将浑浊的河水样品倒入烧杯中，加入明矾粉末搅拌（你一定知道加入明矾的作用：______），溶解后静置一会儿．

（2）将静置后的河水采用下图所示装置进行过滤，写出图中a、b两种仪器的名称：a______；b______．

（3）过滤后得到的水澄清透明，取少量于烧杯中，加入肥皂水并搅拌，发现烧杯中有大量浮渣，则说明右江水是______（填“硬水”或“软水”）．日常生活中如果使用硬水会带来许多麻烦，家庭生活中常用来降低水的硬度的方法是______．

答案

（1）明矾溶于水形成的胶体具有吸附性，能将不溶性固体小颗粒吸附在其表面，从而加快沉降的速率故填：吸附沉降；

（2）据图可知，a是烧杯，b是漏斗，故填：烧杯，漏斗；

（3）硬水中含有的可溶性钙镁化合物能与肥皂水结合产生浮渣，可溶性钙镁化合物受热易转化成不溶性钙镁化合物，故可以使用加热的方法降低水的硬度，故填：硬水，加热煮沸．

单项选择题

可提高麦门冬汤对老年咳嗽的镇咳疗效的西药是（）

A.庆大霉素

B.普萘洛尔

C.磷酸可待因

D.甲基多巴

E.地高辛
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单项选择题

It seems incredible to me that Latin is not taught in schools as a matter of course, especially in a country that is forever lamenting its own (undeniable) mediocrity when it comes to speaking foreign languages. As a 13-year-old, I hardly approached my own Latin lessons with anything resembling enthusiasm—I might have been keener if Aeneas went to the shops occasionally—but I am terrifically grateful I had them, all the same.
The benefits are many. Having a basic grounding in Latin makes learning Romance languages a doodle(轻而易举的事): the fact that I speak English plus three others has less to do with any genetic predisposition—I was hopeless at learning Russian—than with an understanding of the root and provenance of Latin-derived words.
It would be impossible to have a smattering of Latin and find oneself stuck in Italy, provided one managed to persuade the speaker to slow down a bit. And the reason I can (arguably) just about string a sentence together in English—which isn’t my first language—has a great deal to do with understanding, through Latin, the way sentences and grammar work.
Latin also has its own pleasing internal logic: you follow the rules and you get the answer. And I really believe that if you know Latin, you half-speak French already. The British used not to be appalling at languages: my theory is that they only became so during the past century, when Latin stopped being widely taught.
Detractors(恶意批评者) might point out that there is little use in learning a dead language. But Latin is not dead: it’s everywhere. It makes the kind of people who never use two short words when six big ones will do intelligible. It demystifies jargon and legalese. It helps with crosswords. It even forces those of us who are pathologically illogical to think logically every once in a while: I remember the pleasure I felt at school, during Latin translation, when I realized I could create order and sense out of apparent chaos.
Really, Latin’s useful applications are manifold. Watching Who Wants To Be A Millionaire a few weeks ago, I noticed that the question which felled the contestant would almost certainly not have stumped him had he had some Latin. Of all the possible answers, only one had a Latin root that echoed the question. From Cicero to Chris Tarrant in a few easy steps, you can’t say more modem or less dusty than that.

According to paragraph 4, the British ______.

A．have always been terrible in learning Latin

B．used to be good at languages when Latin was taught

C．became good at languages when people stopped learning Latin

D．used to be terrible in languages when Latin was taught
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