I am catching up with some of your recent solutions
posted for the Narada exercises.
In Ex 15-B:
6. There is such a young doctor in this street.
hoti / asuko / taru.no / vejjo / asmi.m /
visikhaaya.m
Asuko taru.no vejjo asmi.m visikhaaya.m hoti.
I would suggest using "atthi" instead of "hoti", thus:
Atthi asuko taru.no vejjo asmi.m visikhaaya.m.
The way it has been explained to me is that "atthi" is
more for "existential" uses, i.e., something exists,
as in the sentence above, whereas "hoti" is
"copulative", i.e. equating something with something
else, e.g. taru.no vejjo braahma.no hoti - the young
doctor is a Brahmin.