How many main mountain ranges does the United States have?
3
3
4
3
5
4
3
5
4
3
5
4
3
5
4
3
5
4
3
5
4
2
3
5
4
2
3
5
4
2
3
5
4
2
3
5
4
2
3
6
5
4
2
3
6
5
4
2
3
6
5
4
2
3
1
6
5
4
2
3
1
6
5
4
2
3
1
6
7
5
4
2
3
1
6
7
5
4
2
3
1
6
7
5
4
2
3
1
6
7
5
4
2
1
6
7
5
2
1
8
6
7
2
1
8
6
7
2
1
8
6
7
2
9
1
8
6
7
2
9
1
8
6
7
10
2
9
1
8
6
7
10
9
1
8
6
7
10
9
1
8
6
7
10
9
1
8
6
7
10
9
1
11
8
6
7
12
10
9
1
11
8
7
12
10
9
1
11
8
7
12
10
9
1
11
13
8
7
12
10
9
11
13
8
7
12
10
9
11
13
8
7
12
10
9
11
13
8
12
5 Mountains
4 mountains