作业

2 F3 since 4 for 5 since 6 since7 for 8 for 9 for10since 11 for 12 since 13 for 14 for 15 for

187'

3 A 4 M 5 I 6 B 7 O8 D9 E 10 G 11 N 12 H 13 J 14 k 15 L

1 b 2 a 3a 4a 5b 6b7a 8a9b
10a 11b 12a 13a 14a 15a 16b 17b 18 b

104'