Tonight I made a mistake too. This mismake show my life lack consistency. I am easy to be interrupted. I must try my best to maintaining stability. Sorry to myself. I wasted 2~3 hours again. I really regret it. I must make full use of every minute to get wasted time back(make up for lost time).
Dexue gave me a job to learn DC. Frankly speaking, I dont know what is DC now. But It will be clear to me.