Where are you going , Jane ?   I'm going to the hospital to see Susan .   I saw her yesterday.She was a little better .   Must I catch a number 7 bus to get there ?   No , you needn't . A number 13 bus will also take you to the hospital .   Number 13 buses run much more frequently , don't they ?   Yes . I caught a number 7 bus yesterday , and they said I had taken a wrong bus .   Thank you , Henry . I'll get a number 13 .   But number 13 buses leave from the center of town.You ' ll have to walk two miles to catch one . 