This answer key accompanies the third edition of Longman Preparation for the TOEFL iBT Test and explains how reading answers connect to evidence in the passages. The supplied material begins with the Reading Diagnostic Pre-Test, offering explanations for twenty questions rather than simply listing the correct letters. It addresses factual and negative factual information, rhetorical purpose, vocabulary, paraphrasing, inference, sentence insertion, and the selection of summary information. The diagnostic passage examines aggression through biological, instinctive, and social learning theories. Its explanations distinguish intentional harm from other behavior, compare spontaneous aggression with responses to provocation, and discuss displacement and catharsis. Other answers trace the influence of role models, rewards, punishment, and fictional violence on learned behavior. These examples show how a reader must preserve the meaning of a sentence and avoid adding claims that the passage does not make. The following sections focus on understanding vocabulary from context and recognizing referents. Vocabulary explanations compare plausible alternatives with synonyms, antonyms, and meanings that do not fit a particular sentence. Reference exercises use examples involving insect colonies, caterpillar feeding behavior, and smartphones to identify what pronouns and substitute expressions represent. Explanations also consider parallel structure, sentence subjects, and cause-and-effect transitions. Used alongside the corresponding exercises, these pages support careful review of mistakes and closer attention to the language that makes an answer defensible.