完形填空 The faster way to travel in a city is by subway. In many big cities, there 1 usually more than one subway lines. How to travel by 2 ? Here is something to know 3 you travel by subway. First, you should choose the right line. If you don't, you will have to get off and take 4 one. Second, you need some coins  (硬币) to buy your 5 . In 6 of the ticket machines, only coins are used. You can change (换) 7 at the ticket office. If you have a prepaid (预付款) card, you can just go ahead. After you buy the ticket, you should 8 the train behind a yellow line. You 9 stand too close to the yellow line. It's 10 . (     )1. A. have (     )2. A. subway (     )3. A. after (     )4. A. the next (     )5. A. food (     )6. A. most (     )7. A. money . (     )8. A. look for (     )9. A. must (     )10.A. dangerous B. has B. bus B. before B. other B. book B. all B. coins B. get off B. mustn't B. safe C. are C. train C. until C. the other C. ticket C. each C. subway C. get on C. have to C. fun D. is D. bike D. as soon as D. another D. map D. few D. ticket D. wait for D. don't have to D. OK