QUES:
Who is it in the following sentence?

My brother put a Barbie that has metal parts in the microwave, so it does not work anymore.

ANS:
the microwave

QUES:
Who is they in the following sentence?

The lumberjacks cut the trees so they could be sold.

ANS:
the trees

QUES:
Who is she in the following sentence?

Jill was writing on a pad for Jane because she needed directions.

ANS:
Jane