2000年，因为儿子在美国麻省理工学院(MIT)攻读博士学位，即将毕业，应学校邀请，我有幸到美国波士顿度过了近三个月的旅美生涯。这也可以说是一次自费考察，短期自费“留学”，尽管只是短暂的三个月，可给我留下了深刻的印象。在美期间，到了美国首都华盛顿，参观了美国历任总 In 2000, I was fortunate to have spent nearly three months in Boston during my travels to the United States because my son is going to graduate from Massachusetts Institute of Technology (MIT) for a doctorate. This can also be said to be a study trip at their own expense and studying abroad for a short period of time at their own expense, though only a brief three months left a deep impression on me. During the visit to Washington, the capital of the United States, he visited all the U.S. presidents