范文為教學(xué)中作為模范的文章，也常常用來指寫作的模板。常常用于文秘寫作的參考，也可以作為演講材料編寫前的參考。范文怎么寫才能發(fā)揮它最大的作用呢？以下是小編為大家收集的優(yōu)秀范文，歡迎大家分享閱讀。
寫動物的英語作文50字 初一寫動物的英語作文篇一
the other is white. they are very lovely. the yellow cat is very naughty.
he likes to play with people. he often runs here and there.
his favourite game is playing with balls, ropes and stones. but the white cat is very gentle.
she likes to wash her face. and she doesn′t like to play with people.
she often jumps onto my knees. i like to give her a bath.
oh, my baby cats bring me much happiness. we are very good friends. i love them.
寫動物的英語作文50字 初一寫動物的英語作文篇二
my favourite animals are pandas. i like them very much because they are gentle
and shy. they are also friendly to people. and they look funny, too. their eyes
are the most interesting part. the black circles around their eyes make them
look like they are wearing glasses or have just been in a fight. their favourite
food is bamboo leaves. they don’t like to move around very much. in fact, they
prefer to sleep all day if they can.
but now pandas are endangered. for one thing, people have destroyed many
of their habitats. for another, they don’t have enough food to eat. we must
think of ways to protect them. i think we should build more panda zoos and plant
more bamboo for them.
i hope everyone can do something for animals, so that we can keep our
world rich and colourful and full of interesting animals.
寫動物的英語作文50字 初一寫動物的英語作文篇三
when the arctic ocean freezes over in the autumn, polar bears set off in search of their favorite meals: fatty ringed seals and bearded seals. by the summer, the sea ice begins to melt and break apart. deprived of access to the tasty seals, polar bears spend the summer fasting. at least, that's what's supposed to happen. as the planet warms, the warmer ice-free season is getting longer and longer. so what's a hungry bear to do?
scientists once thought that polar bears might survive by supplementing their pinniped diet by turning to terrestrial foods like snow geese, their eggs and caribou.
"we've had this debate in the literature about whether terrestrial foods are nutritionally relevant to polar bears during the on-land season when the ice has melted."
university of alberta biologist nick pilfold.
"and we've known for a long time, going back to research in the early 70s, even going to back to early explorer logs, that polar bears will consume terrestrial based foods. but the debate was always whether those foods actually add up, energetically." in other words, do these substitutes provide enough nutrition to make up for the lost seals?
to find out, pilfold and his colleagues estimated the weight lost each day by polar bears in the wilds of western hudson bay during the ice-free season, when they could ostensibly be chowing down on terrestrial foods. then they compared that to the weight lost by bears that are temporarily held in manitoba's polar bear alert program.
while captive, the bears do not eat. they drop about one kilogram each day. but the wild bears, who had access to the arctic snack bar, lost the same amount of weight each day. the results are in the journal physiological and biochemical zoology.
"which is really saying that the terrestrial foods do not have dense enough energy to offset the mass loss. so this idea that bears can just switch from eating sea ice–based food to land food and that's going to help supplement against longer ice-free seasons, that really doesn't show up in the data."
the problem is that polar bears evolved to rely on the marine diet.
"the food on land is protein and carbohydrate based, and the food the polar bears really focus on is fat. fat is the name of the game for these bears; they're highly adapted to absorbing that fat into their system and putting it onto their body as body mass, so they can fast on it later on. and the only thing that's going to provide them with that type of fat are marine mammals. and they can only access those marine mammals when there's sea ice."
adult males can go eight months without food. but younger, sub-adult bears, which are no longer nursing and must hunt, can't last as long without sea ice. so as the arctic warms, younger polar bears will disproportionately die out. leaving the species' survival in doubt.
北冰洋在秋季結(jié)冰以后，北極熊就會出發(fā)去尋求它們最喜歡的食物：富含脂肪的海豹和胡子海豹。海冰在夏季開始融化斷裂。這使北極熊在夏季無法吃到美味的海豹，所以它們進(jìn)入禁食期。至少，情況應(yīng)該是這樣。但是由于地球變暖，溫暖的'無冰季節(jié)越來越長。那饑餓的北極熊要怎么辦?
科學(xué)家曾經(jīng)認(rèn)為，北極熊可能會轉(zhuǎn)向陸地上的食物來補(bǔ)充它們對鰭足類動物飲食的需求，進(jìn)而生存下去，這些陸地食物包括雪雁、雪雁蛋和北美馴鹿。
“文獻(xiàn)中有過這類辯論，即在寒冷融化時(shí)陸地食物是否能滿足北極熊的營養(yǎng)需求?！?/p>
尼克·皮爾福德是加拿大阿爾伯塔大學(xué)的生物學(xué)家。
“通過上世紀(jì)70年代初的研究，還有早期的探險(xiǎn)者日志，我們很早以前就知道，北極熊會以陸地食物為食。但是辯論的焦點(diǎn)在于，這些食物是否能增加北極熊的能量。”換句話說，這些替代食物能否為北極熊提供足夠的營養(yǎng)，彌補(bǔ)不能進(jìn)食海豹帶來的損失?
為了解開這個(gè)疑惑，皮爾福德及同事對西哈德遜灣荒野地區(qū)的北極熊在無冰季期間每天失掉的體重進(jìn)行了估算，從表面上看，北極熊在這段時(shí)間食用了陸地食物。隨后，他們將這一數(shù)據(jù)與通過馬尼托巴北極熊預(yù)警計(jì)劃暫時(shí)捕得的北極熊所失掉的體重進(jìn)行了對比。
在被關(guān)期間，北極熊不吃東西。它們的體重每天大約下降1公斤。雖然野生北極熊能享用北極“小吃”，但是它們的體重每天也同樣會下降1公斤。這一研究結(jié)果發(fā)表在《生理學(xué)和生化動物學(xué)》期刊上。
“顯然結(jié)果表明，陸地食物不能為北極熊提供足以抵消大量損失的能量。所以，北極熊可以從食用海冰下面的食物轉(zhuǎn)向食用陸地食物，并幫助它們對抗日益延長的無冰季這個(gè)觀點(diǎn)，并沒有在這項(xiàng)數(shù)據(jù)中得到證明。”
問題是，北極熊進(jìn)化成了依靠海洋食物的動物。
“陸地食物以蛋白質(zhì)和碳水化合物為基礎(chǔ)，而北極熊需要的食物以脂肪為主。脂肪是這些熊真正需要的東西;它們高度適應(yīng)的情況是，將脂肪吸收進(jìn)它們的系統(tǒng)中，然后把這些脂肪放在身上以增加體重，這樣它們之后就可以依靠這些脂肪來度過禁食期。唯一能提供給北極熊這種脂肪的就是海洋哺乳動物。但是它們只能在有海冰時(shí)食用到這些海洋哺乳動物?！?/p>
成年北極熊可以8個(gè)月不進(jìn)食。但是小一些的未成年北極熊已經(jīng)不再被哺育，它們必須要去獵食，可是它們不能在漫長的無冰季期間一直不進(jìn)食。所以，隨著北極地區(qū)變暖，較小的北極熊將會大批死亡。這使這些物種的生存成為問題。
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