1、Unit 4 Global warming1. even if【用法】even if意为“即使，纵然，虽然”，引导让步状语从句。如：Even if you take a taxi, youll still miss your train.Ill get there, even if I have to walk.【考例1】 He is so busy. He cannot afford enough time with his son _ he wants to. (四川2013)A. even if B. as ifC. because D. before【点拨】选A。由He is so b
2、usy可知，他不能腾出足够的时间陪儿子，虽然（even if）他很想。 【考例2】Look at those clouds!Dont worry. _ it rains, well still have a great time. (北京2012)A. Even if B. As though C. In case D. If only【点拨】选A。由“别担心这些”可知，答语第二句句意为“即使（Even if）下雨，我们仍然会玩得很开心。”as though意为“好像”，引导方式状语从句；in case意为“以防，万一”，引导条件状语从句；if only意为“要是就好了”，主要用在虚拟语气中。
3、2. on behalf of【用法】on behalf of意为“代表”。如：On behalf of the department I would like to thank you all.【考例】 _ everyone here, I wish you a pleasant journey back to your country. (辽宁2013)A. By means of B. On behalf ofC. In search of D. For fear of【点拨】选B。由后面的祝福可知，这是代表（on behalf of）大家的。by means of用，依靠；in sea
4、rch of寻找；for fear of唯恐，以免。3. so long as【用法】so long as意为“只要”，相当于as long as，引导条件状语从句。So / As long as you keep on trying, you will surely succeed.【考例】Ones life has value _ one brings value to the life of others. (江苏2012)A. so that B. no matter how C. as long as D. except that【点拨】选C。一个人的生命有价值的条件是“他给别人的生活带来价值”，故用as long as引导条件状语从句。so that意为“以致于，结果”，引导目的或结果状语从句；no matter how意为“不管怎样”，引导让步状语从句；except that意为“要不是，只不过”。
