Problem: I used an old rag to clean the knife , and then I put *it* in the trash.

Do "it" and "the knife" mean the same thing?

Answer: no

Problem: Then he took a piece of iron the shape of the horse horse's foot , and clapped *it* on, and drove some nails through the shoe quite into its hoof, so that the shoe was firmly on

Do "it" and "shape" mean the same thing?

Answer: no

Problem: Susan knows all about Ann 's personal problems because *she* is indiscreet.

Do "she" and "Susan" mean the same thing?

Answer:
no