3.7.2否定前缀un-=not(不，非)（2）【p61-62】
(1) unusual [ʌn'ju:ʒuəl] a. 不平常的，异常的 【usual ['ju:ʒuəl] a.平常的，通常的】
(2) unfit ['ʌn'fit] a. 不合适的 ，不相宜的；不太健康的，不太健壮的 【fit [fit] a.合适的，适宜的】
(3) bit [bit] n. 一点儿， 少量，
(4) hit [hit] n.打(击)， 冲撞
(5) knit [nit] v. 编织， 结合
(6) pit [pit] n. 坑
(7) sit [sit] v. 坐
(8) wit [wit] n. 智力， 才智
(9) exit ['eksit] n. 出口，安全门
(10) uncertain [ʌn'sə:tn] a. 不确定的 ；易变的 【certain 一定的，无疑的；某些；某个 】
(11) certain ['sə:tn] a.一定的，无疑的；某些；某个 【cert=sure确信，确定；-ain后缀】
(12) uncomfortable [ʌn'kʌmfətəbl] a.不舒服的；不自在的【comfortable ['kʌmfətəbl] a.舒适的； 安逸的；使人舒服的】
(13) comfort ['kʌmfət] n. 舒适； 安慰 v. 安慰
(14) unconditional ['ʌnkən'diʃənəl] a.无条件的；绝对的 【conditional [kən'diʃnəl] a.有条件的；受制约的】
(15) condition [kən'diʃən] n. 条件；状态，状况，情况；地位，身份
【经典例句】
1.It's unusual for him to refuse a drink. 给他酒他不喝, 这事可新鲜.
2.As is usual with children, they soon got tired. 孩子们一贯如此, 他们很快就厌倦了.
6.She is unfit for such a senior position. 她不胜任这种高级职务.
3.He keeps himself fit by running 5 miles every day. 他每天跑五英里以保持身体健康.
4.It takes quite a bit of time to get from London to Glasgow. 从伦敦到格拉斯哥要花很多时间.
5.She hit him on the head with a book. 她用书打他的头.
6.She knitted her son a sweater. 她给儿子织了一件毛衣.
7.A fall into the pit,a gain in your wit.吃一堑，长一智.
8.She sat (down) on the chair and took her shoes off. 她坐在椅子上, 把鞋脱了.
9.I needed time to gather my wits before seeing him again. 我需要先镇定一下才能再次见他.
10.When his ex-wife arrived at the party he made a swift exit. 在聚会上, 他的前妻来到时, 他匆匆离去.
11.The outcome is still uncertain. 结果仍不明朗.
12.One thing is certain: I'm not coming here again. 有一件事可以肯定, 我再也不来了.
13.His unnatural manner made her feel uncomfortable.他那做作的举止使她感觉很不舒服.
14.The patient is comfortable after his operation. 病人手术后感觉良好.
15.The news brought comfort to all of us. 这消息给我们大家带来了安慰.
16.Japan accepted an unconditional surrender in 1945.1945年日本接受无条件投降.
17.Payment of the money is conditional upon delivery of the goods（If the goods are not delivered, the money will not be paid）. 货到方可付款（货不到则不付款）.
18.I've had no exercise for ages; I'm really out of condition. 我已多时没运动了, 现在健康状况欠佳.