Which of the following is Bezout's identity?

Which of the following rational numbers has a non-terminating repeating decimal expansion? $(A)$ $\frac{17}{32}$,$(B)$ $\frac{17}{248}$,$(C)$ $\frac{17}{160}$

Determine whether the rational number $\frac{77}{210}$ has a terminating or non-terminating repeating decimal expansion. If it is terminating,write down its decimal expansion.

Check whether $6^n$ can end with the digit $0$ for any natural number $n$.

The last digit of $2^{m} \cdot 5^{n}$ (where $m, n \in N$) is . . . . . . .

The last digit of $5^{25}$ is .......