题干

在装修房屋时,工人师傅常用一根足够长的透明塑料软管,里面灌入适量的水(水中无气泡),两人各持管的一端靠在墙面的不同地方,当水静止时,在与水面相平的位置做出标记。这样做利用了____ 原理,目的是保证两点在 ____ 。

上一题 下一题 0.0难度 选择题 更新时间:2016-05-31 04:13:54

答案(点此获取答案解析)

连通器,同一水平高度(同一水平线)

同类题2

阅读理解

    It's comforting to think if you were somehow swallowed by a whale, you'd simply hang out in his stomach until he eventually spat you out, unharmed and whole. Unfortunately, your chance of ending up in this type of situation is pretty low.

    In 2012 reporter Ben Shattuck read the records at the New Bedford Whaling Museum Research Library. Despite his extensive research at one of the most comprehensive whaling archives(档案), he failed to find a single report of anyone ever being swallowed alive by a whale. He found plenty of reports of whalers who were bitten or injured by the creatures, and several who died after fighting with a whale, but none related to swallowing.

    With whales' large mouths, it certainly seems possible that a whale could swallow someone whole, so why is it so unlikely? Baleen whales, or whales without teeth, are some of the largest creatures on the planet. Despite their massive size, baleen whales could never get you into their bellies thanks to their relatively small esophagus(食道). These whales are designed to eat small sea creatures, and the opening in their throat is only about as large as a basketball, so you'd never make it that far.

    But what about toothed whales? Sperm whales eat whole seals, so you could easily fit down their throats and into their stomachs. However, once you reached the first of the sperm whale's four stomachs, your journey would probably end quickly. Not only would the whale's stomach acid make quick work of you, but you'd experience a distinct lack of air on the inside. Actually, you're more likely to get eaten or injured as you try to make it past the sperm whale's sharp teeth. Plenty of whalers, have fought with sperm whales and lost their hands or lives due to these mean teeth.

同类题3

阅读理解

    I believe that my country,Poland,is a perfect example for a place where food is particularly important. When we were little children, we began to understand how much a loaf of bread meant to our parents—to some it might sound silly but for me the custom of kissing bread before you started cutting it was simply amazing. It's not so common nowadays to treat food that way,since you hardly ever bake your own bread. Besides, everyone would call you crazy if you tried to kiss every bread roll before you ate them! But though we no longer make our food from scratch (起点), some customs have been kept—that's why I feel so sorry every time I have to throw any food away—even though I no longer live with my parents and nobody would blame me for this anymore!

    Many people of our nation are still working as farmers, eating what they grow and harvest and therefore enjoying everything more. It's widely known that you value more anything that needs your effort in the first place. In most homes in Poland, especially those of farmers, the whole family would try and have their meals together—extremely difficult now, but so rewarding! You can share other members' troubles and successes, give your children some attention, or just sit down for a moment, instead of rushing through life aimlessly. Furthermore, your body,and stomach in particular will be very grateful for such a time!

    In Poland, a wedding,Christmas or even a birthday is celebrated with a great meal. Women in the house get together and cook ,sometimes for a few days before the event,and the extremely good or unusual food will be remembered and widely talked about.

    You cannot over-value the importance of food in the country. What's more, almost everyone in Poland will be as interested in the topic as I am.