描写动物的英语作文
描写动物的英语作文 1
I like dogs, becau they are man’s good friends.
They can do many helpful things to us, such as guarding our hous, greeting guests, helping the police, and so on.
Some trained dogs can even lead the blind people and save people’s lives.
So they‘re treated as our family members.
I hope someday dogs will be in great harmony with human-beings.
描写动物的英语作文 2
纸尿裤和拉拉裤的区别 When the Arctic Ocean freezes over in the autumn, polar bears t off in arch of their favorite meals: fatty ringed als and bearded als. By the summer, the a ice begins to
melt and break apart. Deprived of access to the tasty als, polar bears spend the summer fasting. At least, that's what's suppod to happen. As the planet warms, the warmer ice-free ason 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 gee, their eggs and caribou.
赞扬领导的话简短精辟 "We've had this debate in the literature about whether terrestrial foods are nutritionally relevant to polar bears during the on-land ason when the ice has melted."
University of Alberta biologist Nick Pilfold.
"And we've known for a long time, going back to rearch in the early 70s, even going to back to early explorer logs, that polar bears will consume terrestrial bad foods. But the debate was always whether tho foods actually add up, energetically." In other words, do the substitutes provide enough nutrition to make up for the lost als?
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 ason, 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 den enough energy to offt the mass loss. So this idea that bears can just switch from eating a ice–bad food to land food and that's going to help supplement against longer ice-free asons, that really doesn't show up in the data."
佛说人生经典语录
The problem is that polar bears evolved to rely on the marine diet.
"The food on land is protein and carbohydrate bad, and the food the polar bears really focus on is fat. Fat is the name of the game for the bears; they're highly adapted to abs
orbing 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 tho marine mammals when there's a ice."特长写什么
巽寮
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 a ice. So as the Arctic warms, younger polar bears will disproportionately die out. Leaving the species' survival in doubt.
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北冰洋在秋季结冰以后，北极熊就会出发去寻求它们最喜欢的食物：富含脂肪的海豹和胡子海豹。海冰在夏季开始融化断裂。这使北极熊在夏季无法吃到美味的海豹，所以它们进入禁食期。至少，情况应该是这样。但是由于地球变暖，温暖的无冰季节越来越长。那饥饿的北极熊要怎么办?
科学家曾经认为，北极熊可能会转向陆地上的食物来补充它们对鳍足类动物饮食的需求，进而生存下去，这些陆地食物包括雪雁、雪雁蛋和北美驯鹿。
“文献中有过这类辩论，即在寒冷融化时陆地食物是否能满足北极熊的营养需求。”
尼克·皮尔福德是加拿大阿尔伯塔大学的生物学家。
“通过上世纪70年代初的研究，还有早期的探险者日志，我们很早以前就知道，北极熊会以陆地食物为食。但是辩论的焦点在于，这些食物是否能增加北极熊的能量。”换句话说，这些替代食物能否为北极熊提供足够的营养，弥补不能进食海豹带来的损失?厂房降温
为了解开这个疑惑，皮尔福德及同事对西哈德逊湾荒野地区的北极熊在无冰季期间每天失掉的体重进行了估算，从表面上看，北极熊在这段时间食用了陆地食物。随后，他们将这一数据与通过马尼托巴北极熊预警计划暂时捕得的北极熊所失掉的体重进行了对比。
求职的自我介绍 在被关期间，北极熊不吃东西。它们的体重每天大约下降1公斤。虽然野生北极熊能享用北极“小吃”，但是它们的体重每天也同样会下降1公斤。这一研究结果发表在《生理学和生化动物学》期刊上。
