a. 人造的

future/past/nature/natural/man-made/artificial
记忆：
1. future [ 5fju:tFE ] n. 未来, 将来, 前途, 远景 adj. 未来的, 将来的 Any promising young man will have a bright future in our company.任何有潜力的年青人在我们公司都会有一个美好的未来。
2. past [ pB:st] n. 过去, 往时 adj. 过去的 prep. 越过, 晚于 I have been studying English in the past five years.最近五年我在学英语。
3. nature [ 5neitFE ] n. 自然, 自然界，本性, 天性 It’s not human nature to break the balance of nature. 破坏生态平衡不是人类本性。
5. man-made adj. 人造的 Paper is not natural but man-made.纸不是天然的而是人造的。
6. artificial [ 7B:ti5fiFEl] art, 艺术，fic, 即fac, 做；artificial, 艺术般做的，adj. 人造的, 假的 The diamond in her necklace was artificial, not a real one.她项链上的钻石是人造的，而不是真正的钻石。
另类阅读：
Remember the past and face the future. It’s the natural attitude of most Asians including Chinese towards Japanese. There is no artificial objection to Japan.

轻松一刻
At midnight father saw that his married son leaving home... He asks him: what are you doing?
The son replied: Dad I am fed up with my life! My newly marriage is not going well, my wife and my mum keep fighting with each other! I have to pay bills for my in-laws, and I hate this life!!! I want to go far from here, I want to taste every joy of life, and I want to have every fun of life!!!
Father said: Wait!!!!!!!! I am coming with you