1, B-enroll
2, C-social work
3, C-resources
4, D-Can I help
5, B-call
6, A-environment
7, A-sidewalk
8, C-leaves
9, A-worldwide
10, A-took part
11, D-out
12, B-may
13, D-for
14, A-aim
15, A-outdoor
16, B-register
17, C-Can you
18, B-in order to pass
19, D-traveling
20, A-What can I do for you?