How many main rivers are in Australia?
7
4
4
4
5
3
4
5
3
4
5
3
2
4
5
3
2
4
5
3
2
4
5
3
2
4
5
1
3
6
2
4
5
1
3
6
2
4
5
1
3
6
2
4
5
1
3
6
7
2
4
5
1
3
6
7
2
4
5
1
3
6
7
2
4
5
1
3
6
7
2
4
5
1
3
6
7
2
4
5
9
1
3
6
7
2
4
5
9
1
3
6
7
2
4
5
9
1
3
6
7
2
4
5
8
9
1
3
6
7
2
5
8
10
9
1
3
6
7
2
5
8
10
9
1
3
11
6
7
2
8
10
9
1
11
6
7
2
8
10
12
9
1
11
6
7
2
8
10
12
9
1
11
6
7
8
10
13
12
9
1
11
6
7
8
10
13
12
9
1
11
6
7
8
10
13
12
9
1
11
6
7
8
10
13
12
9
11
14
7
8
10
13
12
128
5 rivers
128
4 rivers
128
5 rivers
7 rivers