新概念二43课.ppt

New words and expressions 生词和短语 pole n. （地球的）极 flight n. 飞行 explorer n. 探险家 lie v. 处于 serious adj. 严重的 point n. 地点 seem v. 似乎 crash v. 坠毁 sack n. 袋子 clear v. 越过 aircraft n. 飞机 endless adj. 无尽的 plain n. 平原 Ask and answer: 1. When did the man successfully fly over the South Pole for the first time ? 2.Who successfully flew over the South pole for the first time ? 3.Would the plane crash? 4.How did they clear the mountain? 5.Why did Byrd now know that he would be able to reach the South Pole ? 6.Was there any difficulties? can Can is one of the most commonly used modal verbs in English. It can be used to express ability or opportunity, to request or offer permission, and to show possibility or impossibility. Examples: I can ride a horse. ability We can stay with my brother when we are in Paris. opportunity She cannot stay out after 10 PM. permission Can you hand me the stapler? request Any child can grow up to be president. possibility Could Could is used to express possibility or past ability as well as to make suggestions and requests. Could is also commonly used in conditional sentences as the conditional form of can. Examples: Extreme rain could cause the river to flood the city. possibility Nancy could ski like a pro by the age of 11. past ability You could see a movie or go out to dinner. suggestion Could I use your computer to email my boss? request We could go on the trip if I didnt have to work this weekend. conditional Could cannot be used in positive sentences in which you describe a momentary or one-time ability. e.g. Yesterday, I could lift the couch by myself. Not Correct 比较can和be?able?to 表示成功地做了某事时，只能用was/were?able?to，?不能用could。 He?could?swim?halfway?before?he?got?tired.?(not correct) He?was?able?to?swim?halfway?before?he?got?tired.(correct) can用于表示“能力”时是指现在的能力，过去或将来的能力通常用was/were?able?to或will/shall?be?able?to表示。  Review can/can’t/could/couldn’t I can dance th