再问个基本的问题

为什么说I have an MBA. 为什么要用an 不是a呢？ 请教！

所有跟帖： 

• because the pronouciation of M -tern2- ♀ (100 bytes) () 06/22/2011 postreply 10:28:32

• 回复：because the pronouciation of M -i999- ♀ (80 bytes) () 06/22/2011 postreply 10:33:56

• Well, only when M is used as the letter M itself and hence proun -tern2- ♀ (196 bytes) () 06/22/2011 postreply 10:51:17

• Not only M -全国牙防组- ♂ (184 bytes) () 06/22/2011 postreply 10:54:37

• 还有：an RN :) -千与.千寻- ♀ (0 bytes) () 06/22/2011 postreply 13:01:26

• a good one! -非文学青年- ♀ (0 bytes) () 06/22/2011 postreply 13:33:17

• Thanks, Learnt -金迷- ♂ (0 bytes) () 06/22/2011 postreply 10:38:05

• 这些规律我都记不住，说的时候就看顺嘴不，“a”不顺嘴“an”顺嘴，那就是“an” -千与.千寻- ♀ (86 bytes) () 06/22/2011 postreply 13:04:21