Problem: No one joins Facebook to be sad and lonely. But a new study from the University of Wisconsin psychologist George Lincoln argues that that's exactly how *it* makes us feel.

Are "it" and "study" the same?
Answer: no

Problem: The foxes are getting in at night and attacking the chickens . I shall have to guard *them* .

Are "them" and "The foxes" the same?
Answer: no

Problem: Bob was playing cards with Adam and was way ahead. If Adam hadn't had a sudden run of good luck, *he* would have won.

Are "he" and "Bob" the same?
Answer: yes

Problem: Mary tucked her daughter Anne into bed, so that *she* could sleep.

Are "she" and "Mary" the same?
Answer:
no