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问题 解答题

①已知，点C在线段AB上，线段AC＝6，BC＝2，点M、N分别是AC和BC的中点，求线段MN的长度；

②根据①的计算过程和结果，设AB＝a，其他条件不变，你能猜出MN的长度吗？请用一句简捷的话表达你的发现规律.

答案

①4②

由已知条件可知，MN=MC+NC，因为点M、N分别是AC、BC的中点，则MC=1/2AC，NC=1/2BC，那么MN=1/2（AC+BC）．

（1）把线段AC=6，BC=2入上式即可；

（2）把AB=a代入前面所列的式子即可．

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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单项选择题

件号栏中件号是按（）的顺序填写。

A、由上而下

B、由下而上

C、由右至左

D、由左至右
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