摘要
Hanged on the wall outside the office of Dr.Chance at the University of Pennsylvania is a thick plaque(4-1:5 feet)dedicated to Dr.Chance by his students at his 90'th birthday,saying桃李天下(Tao Li Tian Xia).This is a traditional Chinese idiom praising great teachers.桃李天下literally means"peaches and plums all over the world".
