Because you're only allowed to ask for
one letter at a time. (If you ask for all the letters at once, there is no challenge at all)
So I'll add M since this is first in your list. Perhaps you, or someone else, can then already guess the rest...
ADEHIMORST
"-e--/, merr-/ -eo--e/!" (.....) "-hat/ time/ --/ the/ moo-/ is/ this/? -o-r/ ----a--/ -o--d/ -a-e-/ a/ dr---e-/ -o--i-/! -et/ I/ tha--/ -o-!"