【国语自产精品视频在】I have been fighting hard for more than 50 years and dedicated to the development of science. One word can tell the characteristics of my most difficult work, this word is failure.The opportunity is to rely on their own fight, success is to need their own efforts. You can do it.

It's not easy to learn at ordinary times, and it's too late to regret it.It has the shortest and perfect life