the revolutionary era

Answer 1

1 b
2 d
3 c
4 c
5 a
6 a,c,d
7 c
8 a
9 d
10 a,b,c
11 c
12 b
13 d
14 c
15 a
16 b
17 b
18 c
19 c

and just type one letter you would've started with for 20 (or 2) and act like your computer erased it