unit5The_Power_of_Nature课件20(人教版选修6).ppt

人教课标版 高二 选修6 Unit 5;Language points;1. Have you ever considered how weak humans are compared with a volcano, hurricane or earthquake ? 你是否想过, 和火山, 飓风或地震 相比人类是何等脆弱。; consider 思考, 主要用于： consider +名词/-ing形式:  He is considering studying abroad. 他正在考虑出国留学。;consider + wh-: We considered how we should help them. 我们仔细考虑应该如何帮助他们。 consider + 副词： Consider carefully before you decide. 要慎重考虑后再作决定。;2. Do you enjoy taking risks? risk n. 风险，危险： He was taking a risk by overtaking on a bend. 他在转弯处超车是在冒风险。 The house is a fire risk. 这房子有起火的危险。; 短语联想： at risk 在危险中: You are at risk if you don’t wear a seat belt. 不系安全带真的会有危险。;at the risk of 冒……危险 At the risk of seeming rude, I must refused your request, I’m afraid. 尽管似乎无理，恐怕我还是必须拒绝你的要求。;3. Having collected and evaluated the information, I help other scientists to predict where lava from the volcano will flow next and how fast. [考点] Having collected and evaluated是动词 -ing形式的完成式, 说明它表示的动作在主要谓语表示的动作之前发生。;[考例1] The storm left, _____ a lot of damage to this area. (2005全国卷I) A. caused B. to have caused C. to cause D. having caused [点拨] “暴风雨破坏”这个动作发生在left之前，故用动词-ing形式的完成式。;[考例2] _____ in the queue for half an hour, Tom suddenly realized that he had left his wallet at home. (北京2004) A. To wait B. Have waited C. Having waited D. To have waited [点拨] 此处强调已等了半个小时，然后才意识到没带钱包，故用动词-ing形式的完成式。;4.Many houses have been covered with lava or burned to the ground. 许多房屋被熔岩覆盖或烧毁。 burn to the ground 指楼等被烧毁 He has no place to live in because his house has been burnt to the ground. 他无处栖身因为他的房子被烧掉了。;短语联想： burn away 烧掉 The wood had burnt away to nothing. 木头已烧成灰烬。;burn down (建筑物) 烧毁： The cinema burnt down last year. 电影院去年被烧毁了。 The school was burnt down by vandals. 学校被人纵火烧毁了。;burn off 烧掉 He was badly injured in the accident, and his hair was burnt off. 他在事故中严重受伤，头发也被烧掉了。 burn out 烧坏 The engine had burnt out. 引