QUES:
Who is it in the following sentence?

I chopped down the tree with my axe because it was sharp.

ANS:
my axe

QUES:
Who is he in the following sentence?

Master Wong had to come to the defense of his pupil, Lun-Xiu, since he managed to anger numerous thugs.

ANS:
Lun-Xiu

QUES:
Who is they in the following sentence?

The assembly line workers were told they had been fired by the company, because they had moved the jobs overseas.

ANS:
The assembly line workers