Question:
The environmentalists were angry at the corporation because they had ignored their proposal.

they
Answer:
the corporation
Question:
Zidane headbutted Zambrotta because he could not control his anger.

he
Answer:
Zidane
Question:
The ski instructors taught the children the basics of skiing because they have much experience to share and teach.

they
Answer:
The ski instructors
Question:
The judges monitor the performance of the competitors to measure their abilities, but they do not decide if they move on to the next round.

they
Answer:

The judges