Study the letter series given below and answer the questions that follow:
$H, D, Y, S, M, W, N, B, Q, P, O, C, R, T, B, L, Z, V, E, G, U, F$
Which two neighbours in the given arrangement are farthest in the alphabetical order?

Each of the following questions is based on the following alphabet series.
$A, B, C, D, E, F, G, H, I, J, K, L, M$
$N, O, P, Q, R, S, T, U, V, W, X, Y, Z$
Which letter is as far from the first letter of the alphabet as the letter $C$ is from the letter midway between $K$ and $R$ in the word $'QUICKSILVER'$?

Find which one word cannot be made from the letters of the given word: $RECOMMENDATION$.

Find which one word cannot be made from the letters of the given word: $SIGNIFICANT$.

Each of the following questions is based on the following alphabet series.
$A, B, C, D, E, F, G, H, I, J, K, L, M$
$N, O, P, Q, R, S, T, U, V, W, X, Y, Z$
If the given alphabet is arranged in reverse order,which letter will be the eighth letter to the left of the seventh letter counting from the right end?

Find which one word cannot be made from the letters of the given word: $CORRESPONDING$.