Solve the following arithmetic problems and sequence patterns.

The answer is $\boxed{0}$.

1.1.2

The answer is $\boxed{500}$.

1.1.3

The answer is approximately $\boxed{0.33 \text{ and } 33.33\%}$.

1.2
To arrange the numbers $0; -32; 6; 20$ in descending order, we list them from largest to smallest.
The order is $\boxed{20; 6; 0; -32}$.

1.3.1

The sequence is $9; 18; 36; ...$. Each term is multiplied by 2 to get the next term ($9 \times 2 = 18$, $18 \times 2 = 36$).

The next number is $36 \times 2 = 72$.
The number after that is $72 \times 2 = 144$.
The missing numbers are $\boxed{72; 144}$.

1.3.2

The sequence is $27; 9; 3; ...$. Each term is divided by 3 to get the next term ($27 \div 3 = 9$, $9 \div 3 = 3$).

The next number is $3 \div 3 = 1$.
The number after that is $1 \div 3 = \frac{1}{3}$.
The missing numbers are $\boxed{1; \frac{1}{3}}$.

1.3.3

$9 - 27 = -18$
$3 - 9 = -6$
The difference is not constant.

$\frac{9}{27} = \frac{1}{3}$
$\frac{3}{9} = \frac{1}{3}$
The ratio is constant.
The pattern in 1.3.2 is an example of a constant ratio. This is because each term is obtained by multiplying the previous term by a constant factor of $\frac{1}{3}$ (or dividing by 3).

1.4

$1 \text{ km} = 1000 \text{ m}$

The answer is $\boxed{3860 \text{ m}}$.