Question

_______________ muchachas son muy feas.

Answer 1

For this case what you should do is choose the third person of the plural correctly.

In the case of English we have that the third person of the plural is:

They

We can then write:

They = The girls

In the case of Spanish, the third person in the feminine plural is:

Ellas

We can then write:

Ellas = Las muchachas

Answer:

Las muchachas son muy feas.

Answer 2

"Las" muchachas son muy feas.