My homework question is to name the four broad types of like-kind exchanges? Are they 1) Receipt of boot 2) Giving boot 3) Assumption of liabilities 4) Three-party exchanges

I wasn't sure.

There are five types defined at this web site:
http://www.transunionexchange.com/frequently_asked_questions.asp#types

They follow the question:
"What are the different types of 1031 like-kind exchanges?"

The types are called:
(1)simultaneous
(2)delayed
(3)reverse
(4)build-to-suit, and
(5)personal property exchange
More about what they mean can be found at the referenced web site