SAT® is a registered trademark of the College Entrance Examination Board, which was not involved in the production of, and does not endorse, these products. ACT® is a registered trademark of ACT, Inc. Houghton Mifflin Harcourt has no affiliation with ACT, Inc. and our products are not approved or endorsed by ACT, Inc. *AP is a registered trademark of the College Entrance Examination Board, which was not involved in the production of, and does not endorse, these products. GRE is a registered trademark of Educational Testing Service (ETS). This product is not endorsed or approved by ETS. GMAT is a registered trademark of the Graduate Management Admission Council (GMAC®).