平仄

There is only a week ahead for my exam. I don't know who can finish all the preparation because it is so easy to forget what one has read. The Chinese cousre is also a pain for me. Until now, I have hard time to distinguish between 平仄。I know 陰平和陽平, but it comes to those poems, every word seems to be 仄 all of a sudden. I don't know why. I guess I have to cross my fingers if it happens on the exam sheet.