mysterious: suggests a quality that excites wonder, curiosity, or surmise yet baffles attempts to explain it: couldn't account for the ~ noise upstairs.                (baffle: to confuse and puzzle使疑惑，难以解决)


inscrutable: applies to something that defies one's efforts to examine or investigate it or to interpret its significance or meaning: sat calmly with an ~ look on her face.             (defy拒绝抗拒，使无法)


arcane: implies a quality that is beyond comprehension because known or knowable only to the possessor of a restricted body of knowledge: a book filled with spells and ~ lore.    (lore口传的知识)


mysterious神秘的: 让人惊叹好奇猜想但难以解释，inscrutable难以捉摸的神秘的: 让人难以调查研究解释，arcane神秘的: 超出认知，只限于少数人知道


记忆方法: 1) 首字母AIM目的<==神秘

              2) 神秘的意思是无法发现理解解释mean beyond one's powers to discover, understand, or explain.首字母AIM目的<==神秘