Which one word can be formed from the following letters?
$a, a, d, e, f, g, r, s, u$

$A$ group of letters is given which are numbered $1, 2, 3, 4,$ and $5$. Below are given four alternatives containing combinations of these numbers. Select the combination of numbers so that the letters arranged accordingly form a meaningful word.
$R, A, C, E, T$
$1, 2, 3, 4, 5$

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

Arrange the given words in alphabetical order and choose the one that comes first.

If each alternate letter beginning with the first in the word $WORKING$ is replaced by the next letter in the English alphabet and each of the remaining letters is replaced by the previous letter in the English alphabet,which of the following will be the fourth from the right end after the replacement?

How many independent words can $HEARTLESS$ be divided into without changing the order of the letters and using each letter only once?