a. 神秘的, 难解的, 不可思议的

◆记忆方法一：
联想方式：mysteri～mystery（神秘）；ous（形容词后缀）
记忆方法：mystery的形容词形式。

riddle/ridiculous/absurd/myth/mysterious
记忆：
1. riddle [ 5ridl ] n. 谜, 谜语, 神秘人物 Can you work out this a riddle?你能猜出这个谜语吗？
2. ridiculous [ ri5dikjulEs ] adj. 荒谬的, 可笑的 What ridiculous remarks he made at the gathering! 他在会上的发言多可笑啊！
3. absurd [ Eb5sE:d] ab-surd (adj. 无道理的, n. 无理数) adj. 荒谬的, 可笑的 Their request is absurd. 他们的要求是荒谬的。
4. myth [ miW] 音“秘事”，“神秘的事” n. 神话 A large number of idioms can find their roots in ancient Greek myths. 大量的习语可以在希腊神话里找到出处。
5. mysterious [ mis5tiEriEs] adj. 神秘的 They're being very mysterious about their holiday plans. 他们把他们的假期计划弄得神秘兮兮的。
另类阅读：
Mr. Li has a mysterious ability to work out riddles. However ridiculous it will be, he can find the answer. Some people say that he gets the inspiration from ancient myths. Don’t you think it’s absurd?
轻松一刻：
Many people came to a millionaire's funeral, one of whom cried bitterly.
"You have to face it." other people tried to comfort him, "Is the dead your father?"
"No," the young man cried more bitterly, "why was he not my father..."