Unit 2 Video Time 课件-2022-2023学年高中英语人教版(2019) 必修第二册

Wildlife protection Unit 2 Video Time 1. Learn to get information from watching a video; 2. Learn to guess what the video is about by getting information from the questions; 3. Learn to collect characters’ opinions in a video; 4. Learn to express your opinion on wildlife protection. Lead-in There are 3 different kinds of elephant species. the African bush elephant, the African forest elephant, and the Asian elephant 1 An elephant’s trunk is an all-purpose tool. Elephants use their trunks not only to breathe, smell and eat, but to grasp the trees, pick up objects weighing as much as 700 pounds, dig for water, and give themselves showers. 2 An elephant’s ears help to dissipate heat (散热). The large surface area of its ears is lined with many blood vessels, which take heat away and thus help to cool the temperature down in the hot sun. 3 Elephants are extremely intelligent animals. Not only can elephants use tools with their trunks, but they also display a high degree of self-awareness (for example, recognizing themselves in mirrors) and empathy(同感) towards other members. 4 Elephant groups are dominated by females. Elephants have a unique social structure: males and females live apart. Three or four females, together with their young, live together in groups of up to a dozen, while males either live alone or form smaller groups with other males. 5 Pregnancy(孕期) of the elephant lasts almost two years. About 22 months, African elephants have the longest gestation period of any land mammal (陆地哺乳动物). Newborn elephants weigh about 110kg, and they usually have to wait at least four or five years with their mother. 6 Elephants evolved(进化) over 50 million years. Elephants used to be a lot more common than they are today. From the fossil evidence, the progenitor(始祖) of all elephants was tiny, pig-like, which lived in northern Africa about 50 million years ago. 7 Elephants are important parts of their ecosystems(生态系统). Elephants have an great influence on their habitats, trees,