Pls help and if u put a link or fake answer i will report u pls thank u

What is one purpose of the prologue in sugar changed the world

American history (is, are) studying the american colonies.

Identify the sentence in which the underlined word or words are punctuated incorrectly. a) pam was (well prepared) for the debate. b) she had (read three quarters) of the material more than once. c) she has always been (self assured). d) the winner needs a (two-thirds) majority of the votes.