完形填空。 Japanese high school students do not drive cars. Many of them either walk 1 ride bicycles if the distance is not too great. In other 2 , a lot of students have to 3 public buses and trains, often changing lines several times in order to reach their 4 . It is common for some students to 5 two or more hours each day on 6 transportation. After junior high school, students attend schools based 7 standardized high school entrance examination scores. As a result, some students travel a great distance to 8 the school. The school day begins at 8:30, so students may leave home 9 6:30. While some students sleep or study during their long travel, public transportation also 10 a chance for socializing with peers (同龄人). Students 11 to school are regulated by school policies. These policies may prohibit 12 activities in public -chewing gum, consuming snacks, 13 books while walking - anything that might reflect 14 on the reputation of the school. Each school has a unique 15 that makes its students easily identifiable to 16 . School policies often require students to 17 on buses and trains, 18 seats open for other passengers in order to show thoughtfulness towards others. In practice, 19 , students tend to relax 20 they move farther away from school. ( )1. A. but ( )2. A. cases ( )3. A. go ( )4. A. homes ( )5. A. take ( )6. A. public ( )7. A. in ( )8. A. go ( )9. A. as early as ( )10. A. gives ( )11. A. on the way ( )12. A. sure ( )13. A. carrying ( )14. A. worse ( )15. A. uniform ( )16. A. the teachers( )17. A. silence ( )18. A. having ( )19. A. however ( )20. A. which B. or B. schools B. have B. destinations B. cost B. private B. at B. leave B. as late as B. offers B. in the way B. certain B. taking B. well B. hairstyle B. the students B. sit B. getting B. but B. as C. and C. areas C. take C. companiesC. spend C. school C. on C. attend C. as hurry as C. sends C. by the way C. special C. holding C. badly C. schoolbag C. the public C. seat C. putting C. even C. that D. nor D. countries D. get D. classrooms D. have D. government D. to D. pass D. as long as D. takes D. at the way D. probable D. reading D. truly D. playground D. the s D. stand D. leaving D. still D. so