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: Jim signaled the barman and gestured toward *his* empty glass

Are "his" and "Jim" the same?
Answer: yes

Problem: Even before they reached town , they could hear a sound like corn popping. Dora asked what *it* was, and Dad said it was firecrackers.

Are "it" and "sound" the same?
Answer: yes

Problem: Sam took French classes from Adam , because *he* was known to speak it fluently.

Are "he" and "Sam" the same?
Answer:
no