题干

某物体运动的s﹣t图象如图所示,由图象可知(  )

A:在0﹣60s内物体一直在运动

B:在20﹣40s内物体的运动速度为5m/s

C:物体在0﹣20s比在40﹣60s内运动得快

D:在0﹣60s内物体运动的平均速度为10m/s

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答案(点此获取答案解析)

D

同类题4

阅读《民以“食”为天》,回答下面小题。

民以“食”为天

俞水生

    ①自古以来,中国就有“民以食为天”的说法。中国人在饮食文化上追求精神上的美感和愉悦,讲究色、香、味、形俱佳。中国饮食不仅内容丰富,其背后蕴含的文化也非常丰厚。

    ②中国疆域辽阔,地形多样,加上气候多变,这就为中国人的饮食提供了大量的动植物原料,并形成了汉民族的基本饮食结构特征:以粮食作物为主食,以丰富的动植物作为副食。

    ③米食和面食是汉族主食的两大类型。南方因气候湿热,多种植稻类,故以米食为主;北方气候相对干冷,多种植小麦,则以面食为主。

    ④与丰富的主食相对,作为副食,中国莱肴在长期烹饪中出现了许多流派,并形成不同类型的地方菜系。其中,粤莱、川莱、鲁莱、淮扬莱、浙菜、闽莱、湘莱、徽莱被称为“八大菜系”。不同的莱系,其口味具有很大的不同。过去,人们常把中国人的口味概括为南甜、北咸、东辣、西酸。此说在一定程度上道出了我国饮食文化的地区差异,也反映了人们的口味与地理环境存在着相应的联系。譬如,喜辣的饮食习俗多与东部地区气候潮湿有关,经常吃辣可以驱寒祛湿;过去新鲜蔬莱在北方是罕见的,人们习惯把莱腌制后慢慢食用,这样,北方大多数人就养成了吃成的习惯。

    ⑤除了地理环境因素外,各地的烹饪方法,包括配料、调味、火候、刀工等不同要求,都是形成不同菜肴类型的重要因素。我们在品尝美味佳肴时,往往会说这道莱好吃,然而,若要进一步细究为什么“好吃”,恐怕一般人就讲不清楚了。这说明,中国饮食似乎有着一种难以言传的奥妙。这种奥妙,关键在于它的味道。与西方“菜生而鲜,食分而餐”的饮食传统相比,中国烹饪更讲究调和之美,这是中国烹饪艺术的精妙之处。美味的产生在于调和,使食物的本味、配料和调料,交织融合在一起,使之达到中和之美的最佳味道。

    ⑥中国很早就有“礼乐文化始于食”的观念。从古到今,中国人喜欢把饮食与节庆、最佳味道礼仪活动结合在一起,每逢年节或婚丧寿辰,都会举办各种宴请活动。在节日里,人们通过相应的饮食活动既可加强亲友联系,又可活跃节日的气氛。过节的菜肴也有讲究, 经常通过谐音、双关等方式,表达吉祥、祝福的寓意,如“鸿运当头”“全家福”等。

    ⑦一个地区的饮食礼俗具有相对的稳定性,但并不是一成不变的。近年来,随着经济的快速发展和生活水平的不断提高,人们在吃的方面已不满足于吃饱、吃好,而是对“吃什么”和“怎么吃”讲究起来。显然,这已不单是为满足口欲而吃,主要是为健康、长寿而吃了。

同类题5

阅读理解

    Have you ever found yourself in this situation:You hear a song you used to sing when you were a child-a bit of nostalgia(怀旧)or "blast from the past,"as we say.But it is not a distant childhood memory.The words come back to you as clearly as when you sang them all those years ago.

    Researchers at the University of Edinburgh studied the relationship between music and remembering a foreign language.They found that remembering words in a song was the best way to remember even one of the most difficult languages.

    Here is what they did. Researchers took 60 adults and randomly divided them into three groups of 20.Then they gave the groups three different types of "listen-and-repeat" learning conditions.Researchers had one group simply speak the words.They had the second group speak the words to a rhythm,or beat.And they asked the third group to sing the words.

    All three groups studied words from the Hungarian language for 15minutes.Then they took part in a series of language tests to see what they remembered.

    Why Hungarian,you ask ? Researchers said they chose Hungarian because not many people know the language.It does not share any roots with Germanic or Romance languages,such as Italian or Spanish.After the tests were over,the singers came out on top.The people who learned these new Hungarian words by singing them showed a higher overall performance.They did the best in four out of five of the tests.They also performed two times better than those who simply learned the words by speaking them.

    Dr.Katie Overy says singing could lead to new ways to learn a foreign language.The brain likes to remember things when they are contained in a catchy 3,or memorable 4,tune 5.

    Dr.Ludke said the findings could help those who struggle to learn foreign languages.On the University of Edinburgh's website Dr.Ludke writes,"This study provides the first experimental evidence that a listen-and-repeat singing method can support foreign language learning,and opens the door for future research in this area."