I think "old" may be a correct word to fill in.It is worth mentioning that "the old" in your sentence means "old people" but "the senior" is more polite than "the old".
Hope that helps.
Lilly
I think "old" may be a correct word to fill in.It is worth mentioning that "the old" in your sentence means "old people" but "the senior" is more polite than "the old".
Hope that helps.
Lilly