How many astronauts have walked on the moon as of 2020?
12
3
3
2
3
2
1
3
2
1
3
2
1
4
5
3
2
1
4
5
3
2
1
4
5
3
2
1
4
5
6
3
2
1
4
5
6
3
2
1
4
5
6
3
2
1
7
4
5
0
6
3
2
1
7
4
5
6
0
3
2
1
7
4
5
6
3
2
1
7
4
0
5
6
3
2
1
7
4
5
0
6
3
2
8
1
7
4
5
6
3
2
8
1
7
4
5
9
6
3
2
8
1
7
11
4
5
9
6
3
2
8
1
7
11
4
5
9
6
3
2
8
1
7
11
4
5
9
6
2
8
1
7
11
4
5
9
6
12
8
1
7
11
4
13
5
10
9
6
12
8
7
11
4
13
5
10
9
16
6
12
8
7
11
4
13
5
10
9
16
6
12
8
7
11
13
10
9
16
6
12
8
20
7
11
13
10
9
16
6
12
8
20
11
112
66
112
69
66
132
133