```ts
/**
 * Flips the order of elements in a pair.
 * @param pair - The pair to flip.
 * @returns A new pair with the elements in reverse order.
 */
export function flipOne(pair: string[]): string[] {
  if (pair.length !== 2) {
    throw new Error("Pair must contain exactly two members.");
  }
  return [pair[1], pair[0]];
}

/**
 * Flips the order of elements in each pair of a list.
 * @param pairs - The list of pairs to flip.
 * @returns A new list with each pair's elements in reverse order, preserving the original order of pairs.
 */
export function flipAll(pairs: string[][]): string[][] {
  return pairs.map(flipOne);
}
```