2017年9月21日雅思阅读机经预测超小范围版!雅思阅读考试的文章大多来自于书本、杂志。期刊或者报纸等。所以考生可以在备考中多阅读相关资料背景知识。下面
点击查看》》
点击查看》》
点击查看》》
Hibernation 动物
重复年份 20141220 20120512 20100520
题材 动物
题型 单选+summary+判断题
| 2017年9月21日雅思机经预测汇总 | |
文章大意 主要讲了动物冬眠的情况等。
Hibernation is a state of inactivity and metabolic depression in endotherms. Hibernation refers to a season of heterothermy that is characterized by low body temperature, slow breathing and heart rate, and low metabolic rate. Although traditionally reserved for "deep" hibernators such as rodents, the term has been redefined to include animals such as bears and is now applied based on active metabolic suppression rather than based on absolute body temperature decline. Many experts believe that the processes of daily torpor and hibernation form a continuum and utilize similar mechanisms. The equivalent during the summer months is known as aestivation. Some reptile species (ectotherms) are said to brumate, or undergo brumation, but any possible similarities between brumation and hibernation are not firmly established. Some insects, such as the wasp Polistes exclamans, hibernate by aggregating together in groups in protected places called hibernacula.
Often associated with low temperatures, the function of hibernation is to conserve energy during a period when sufficient food is unavailable. To achieve this energy saving, an endotherm will first decrease its metabolic rate, which then decreases body temperature. Hibernation may last several days, weeks, or months depending on the species, ambient temperature, time of year, and individual's body condition.
Before entering hibernation, animals need to store enough energy to last through the entire winter. Larger species become hyperphagic and eat a large amount of food and store the energy in fat deposits. In many small species, food caching replaces eating and becoming fat.[4] Some species of mammals hibernate while gestating young, which are either born while the mother hibernates or shortly afterwards.
For example, the female polar bear goes into hibernation during the cold winter months to give birth to her offspring. She loses 15–27% of her pre-hibernation weight and uses stored fats for energy during times of food scarcity, or hibernation. It is evident that pregnant female polar bears significantly increase body mass prior to hibernation, and this increase is further reflected in the weight of their offspring. The fat accumulation prior to hibernation in female polar bears enables them to provide a sufficient and warm, nurturing environment for their newborns
Newly Hatched birds 动物
Fluoridation in the water 医疗健康
Coastal sculpture 艺术
Trade 发展史 20160109B 20120728
Children and robot 科技
Culture and Communication人文社科
Ancient Greek Coins 人文社科
Darkside of Technological Boom 科技
Children's adults 文学
Expert in musician 人文社科
Skink in New Zealand 动物
Solving an Arctic Mystery 人文社科 20160521 20141025
Aquaculture in New Zealand农业
The meaning of history study 人文社科
Birds intelligence 动物
Ocean power 能源
Who should look after the child? 人文社科
Paper money 发展史
The tuatara-past and future 动物
Gesture 人文社科
Voynich manuscript 考古
Food Addictive 工业
Japan's ancient pottery 历史
Fish communications 动物
New Zealand Home Textile Craft 人文社科
Sweet Trouble–Australia sugarcane industry农业
The Grimme Fairy Tale 人文社科
We have star performers 商业管理
Blind to Change 心理学
Tick Tock Body clock 生物 20161013 20121013
The importance of being playful 人文社科
When did music begin? 艺术 20160528 20130216
Dust and American 环保
Human Rights to animal 人文社科
The power of music 艺术 20160109A 20131212*
Odd and curious money 人文社科
The history of Russian Ballet
Unique golden textile 工业
Consumer advertisement 商业管理
Australia Parrots 动物
Egypt‘s Sunken Treasures考古 20150509 20120331
Alcohol fuel in England 能源