25 multiple-choice questions in College Board exam style. Each has four choices and a full explanation of why each option is right or wrong.
Read the question carefully before looking at the choices. Many APES questions have answers that look almost identical; small wording differences matter.
Eliminate before guessing. APES distractors often include true statements that don't answer the actual question. Cross out anything irrelevant first.
Energy flows, matter cycles. If a question is about energy, expect a one-way, loss-heavy process. If it's about a nutrient, expect a closed loop.
Read the explanations even when you got it right. Each one teaches a small fact that often returns in a different form on the exam.