QUESTION:
Customer Support fields the questions of their customers so they could receive immediate assistance.
Who is "they"?

ANS:
their customers

QUESTION:
Penguins tend to stay on land to avoid killer whales, but they do need to go in the water for food at times.
Who is "they"?

ANS:
Penguins

QUESTION:
A policeman saw John Edwards commit the crime, so he was arrested.
Who is "he"?

ANS:
John Edwards

QUESTION:
The infection spread throughout the building because it was ventilated.
Who is "it"?

ANS:
the building