题干

如图,零件的外径为16cm,要求它的壁厚x,需要先求出内径AB,现用一个交叉钳(AD与BC相等)去量,若测得OA:OD=OB:OC=3:1,CD=5cm,你能求零件的壁厚x吗?

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解答:∵OA:OD=OB:OC=3:1,∠COD=∠AOB, ∴△COD∽△BOA. ∴AB:CD=OA:OD=3:1. ∵CD=5cm, ∴AB=15cm. ∴2x+15=16. ∴x=0.5cm.

同类题2

   (One day Alice runs after a strange rabbit and comes into a deep hole. She becomes smaller when she wakes up the next day. She finds herself in a wonderland with many amazing things inside.)
   The Caterpillar(毛毛虫) and Alice looked at each other for some time in silence. At last the Caterpillar took the pipe out of its mouth, and said to her in a tired, sleepy voice.
   “Who are YOU?” said the Caterpillar.
   This opening for a talk couldn’t make Alice at ease. Alice replied, rather shyly, “I----I hardly know, sir, just at present ----at least I know who I was when I got up this morning, but I think I must have been changed several times since then.”
   “What do you mean by that?” said the Caterpillar, “Explain yourself!”
   “I can’t explain MYSELF. I’m afraid, sir.” said Alice, “because I’m not myself, you see.”
   “I don’t see.” said the Caterpillar.
   “I’m afraid I can’t put it more clearly.” Alice replied very politely, “for I can’t understand it myself. And being so many different sizes in a day is very puzzling.”
   “It isn’t.” said the Caterpillar.
   “Well, perhaps you haven’t found it so yet.” said Alice. “But when you have to turn into a chrysalis(蛹,茧)----you will some day, you know ----and then after that into a butterfly, I think you’ll feel it a little stranger, won’t you?”
   “Not a bit.” said the Caterpillar.
   “Well, perhaps your feelings may be different.” said Alice. “All I know is, it would make ME feel very strange.”
   “You!” said the Caterpillar scornfully. “Who are YOU?” The question brought them back again to the beginning of the talk. Alice felt a little angry because the Caterpillar was making such VERY short sentences. She drew herself up and said very seriously, “I think you ought to tell me who YOU are first.”
   “Why?” said the Caterpillar.
   Here was another puzzling question. As Alice could not think out any good reason, and as the Caterpillar seemed to be very unpleasant, she turned away.
   “Come back!” the Caterpillar called after her. “I’ve something important to tell you!”
   This certainly gave Alice some hope. Alice turned and came back again.

同类题4

阅读理解

    An Indian movie about two sisters has become a huge hit in China. The Hindi language film, called Dangal, has earned almost $ 170 million in China since its release there on May 5.

    Much has been written about why Dangal has enjoyed such big success in China. Some people say one reason is that the film's star and producer, Aamir Khan. He is famous in India's Bollywood film industry. Two of his earlier films were also big hits in China.

    Khan's popularity was clear after he got more than 600,000 followers on the Chinese social media service Sina Weibo within two months of joining. But he is not the only reason that the film strongly connects with audience across China. Media has pointed out how it shows similarities between parental systems in China and India.

    Dangal is based on the true story of a man who enjoyed the sport of wrestling (摔跤). He competed as a wrestler, but never could achieve his lifelong dream: winning a gold medal. As a father, he wanted his son to win the medal. But his wife only gives birth to daughters. So he finally decides to train them to be world-class wrestlers.

    The movie is more serious than most Bollywood productions, which tell happy love stories and include colorful music and dance performances.

    Edward Chan is a professor at the Hong Kong Polytechnic University. He says the strict way of parenting in the film is something people in China can easily relate to. “I think the father role described by the movie in India is quite similar to the culture, especially the traditional culture in China.”

    The Chinese government-supported Global Times newspaper pointed that movie critics (评论家) in China did not like Dangal. Most of them agree with the fact that the father in the film was forceful in pushing his daughters to become wrestlers. But the film Dangal is really aimed to educate children to work for their dreams.