1、Unit 15 Welcome to San Francisco预习导学学习本单元所掌握的重点知识单词（四会要求）Trolley bu s, normally, quick, line, bridge, rather, public, narrow, ad vantage, advise, market, debate, engine, speed, bay, streetc ar, connec t, district, railway, trip, wise, include短语1. advise sb. not to do sth.2. enjoy our good public tra
2、nsit3. old-time trolleys4. travel up and down Market5. the center of many o f debates6. the butt of many jokes.7. depend on8. the speed of the cable9. 9.5 miles an hour10. never more, never less11. offer a wide view of the city an d bay12. such as13. make another suggestion. Dressing in layers14. a wise decision15. 15. 15. mak e up16. 16. 16. many different kinds of weat her句 型：Would you like to come to San Francisco for a visit?No visit to San Francisco is complete without taking a ride on a cable car阅读文章总结一下说明文的写作方法
