Proactive suppression refers to the interference effect of the materials learned first on the materials learned and memorized later; Retroactive suppression refers to the interference effect of the materials learned later on the materials learned and memorized first. According to the definition above, Which of the following options only include inverse suppression:. ['The middle paragraph is often the most difficult to remember when memorizing the text.', 'People generally have the best memory in the morning and night.', 'After learning the English alphabet, the previously learned Pinyin alphabet will be misread.', "After a head injury, I can't recall what happened before."]