✔ 最佳答案
Because one is the American pronunciation, while the other is British style.
There are also words which most people mispronounced, and has gradually become accepted, so they are widely used and barely anyone know that they are wrong. eg. Discount (the one on E dictionary is right, and the are NO other ways to pronounce, just that the ENTIRE world doesn't know the right pronounciation, even the teachers,
Hope that I can help you ^^
2013-10-02 20:17:48 補充:
Both of them can be found ^^
hope that I can help you XP