time1:1m51s
time2:1m45s
time3:1m03s
time4:1m31s
warming up : 30s
time5:1m36s
写的回忆一不小心被删掉了~~~~(>_<)~~~~
obstacle:
第一次:4m18s 没看太懂
inside trading was legal before 2008, and led to 2008 financial crisis.
government begin to warn inside trading.
第二次:3m59s