Sleep research has continually shown that children spend more of their night getting deep sleep than do adults. This deep sleep corresponds to what stage(s) of sleep?

Every person is genetically unique, with the exception of ______ twins, triplets, quadruplets, and so on

Fill in the blank with correct word

Another name for a "fuzzy" concept is a(n)

a. prototype. b. schema. c. heuristic. d. algorithm. e. natural concept.