US no longer the land of opportunities, In 1989, when structural biologist Shi Yigong got his bachelor’s degree from Tsinghua University, 71% of the 2,251 went to US and stayed. Today is less than 7%. 美國不再是機會之地，1989年結構生物學家從清華大學獲得學士學位時，2251人中71%去了美國並留下來。 今天還不到7%.