Tom is looking for his key to his bike. He cant find it .He has lost his key to his bike.He lost it a short time ago and he still doesnt have it. He cant ride his bike to go to school.He looks worried.Definition Definition 2.过去某一时间点发生的动作持续 到现在或 还将持续下去。1.过去某一时间点发生的动作对现在产生影响。I have learned English for ten years.I have learned English for ten years.We have visited your school before.We have visited your school before.He has lost his key to his bike.He has lost his key to his bike.He has lived in London since ten years He has lived in London since ten years ago.ago.have / has + past participle A: Ive looked at your resume. I see you work in a hotel. B: Yes, I do. A: How long have you had this job ? B: Ive had this job for only a shot time. But I have a lot of experience in the hotel business. In fact, my parents own a hotel in Mexico. A: How long have your parents owned a hotel? B: Most of their lives. A: Have you seen your parents recently ? B: Yes, I have. My mother has been to the U.S. a few times to see me. But my father has never been here because someone has to stay at the hotel all the time. Hes told me many times, “When you are an owner of a business ,you dont have time for vacations. ” But I dont want to be an owner now. I just want a job as a manager. Have you filled the position yet ? A: No, I havent. Ive already interviewed several people A: _ your brother _ a new watch? (buy )B: Not yet.Key Key wordswordsHas bought yet A: _ you ever _ to the park? ( be )B: Yes, I went there last summer. Key Key wordswordsHave been yet ever I _ never _ of anything like that. (hear )Key Key wordswordshave heard yet ever never Tom _ in the factory since heleft school ten years ago. (work )Key Key wordswordshas worked yet ever never since A: How long _ you _ in this school? (teach )B: For 6 years. Key Key wordswordshave taught yet ever never since for I _ just _ the desk, you can take it to your classroom . (mend )Key Key wordswordshave mended yet ever never since for just _ you _ the Forbidden City(紫禁城) before ? (visit ) Key Key wordswordsHave visited yet ever never since for just before He _ already _ a job. (find) Key Key wordswordshas foundyet ever never since for just before already We _ only _ the first five questions so far. (discuss ) Key Key wordswordshave discussed yet ever never since for just before already so far They _over 24,000 fruittrees up to now . (plant )Key Key wordswordshave planted yet ever never since for just before already so far up to now Great changes _ in Beijing in the past 10 years. (take place )Key Key wordswordshave taken place yet ever never since for just before already so far up to now in the past 10 years He _ a lot of good thingsin his life. (do )Key Key wordswordshas done yet ever never since for just before already so far up to now in the past 10 years in his life I _ her lately. ( not see )Key Key wordswordshavent seen yet ever never since for just before already so far up to now in the past 10 years in his life lately I _ him recently. (not hear from ) Key Key wordswordshavent heard from yet ever never since for just before already so far up to now in the past 10 years in his life lately recently He _ in this city ever since then. (live )Key Key wordswordshas lived yet ever never since for just before already so far up to now in the past 10 years in his life lately recently ever since then He _ in this highschool till now. (teach )Key Key wordswordshas taughtyet ever never since for just before already so far up to now in the past 10 years in his life lately recently ever since then till nowhave/has have/has been tobeen to have/has have/has gone togone to have/has have/has been inbeen in1. Bill 1. Bill has gone tohas gone to London , he will come back tomorrow. London , he will come back tomorrow. 2. A: Where are the twins? B: They 2. A: Where are the twins? B: They have gone tohave gone to the cinema. the cinema. 3. I 3. I have been tohave been to Paris twice. He Paris twice. He hashas never never beenbeen there. there. 4. A: 4. A: Have