Yao Ming’s sports life1980was born1989started playing basketballhas been playing21yearsHe started playing basketball in 1989.He has been playing basketball since 1989.He has been playing basketball for 21 years.2010playsHe has been playing basketball since 21 years ago. When did Yao Ming start playing basketball?How long has Yao Ming been playing basketball? 姚明 1980:be born1989 ~now: basketball playerHe started playing basketball in 1989.He has been playing basketball since 1989.He has been playing basketball for 21 years. 成龙（ Jackie Chan ）1954:be born1961~now: actHe has been acting for 49 years. since 49 years ago.How long has Jackie Chan been acting? He has been acting since 1961.When did Jackie start acting?He started acting in 1961. Vicky2003~now:teach EnglishHow long has Vicky teaching English?She has been teaching English for 7 years.She has been teaching English since 2003.She has been teaching English since 7years ago.When did Vicky start teaching?She started teaching in 2003. A: How long have you been studying here?B: I have been studying here … 1.He watched TV for 3 hours last night.2.He has been watching TV for 3 hours.3.He has been watching TV since 3 hours ago. =? 1.How long did he watch TV last night?Did he watch TV for 3 hours last night?Yes, he did. / No, he didn’t.2.&3. How long has he been watching TV? Has he been watching TV for 3 hours?Yes, he has. / No, he hasn’t. I have been skating for five hours. 时态－现在完成进行时have / has 是助动词 been 是 be 的过去分词表示从过去开始一直持续到现在的动作，并有可能持续下去．（一）构成形式：have / has been + Ving (The Present Perfect Progressive Tense)他们已工作两小时了。They have been working for two hours since 2 hours ago. for 和表示一...
