唯一会说中文的美国总统，太太也会说中文，夫妻俩不想让旁边的人知道他们在说啥的时候，就用中文交流。

"Before entering the White House,Hoover and his wife learned fluent Mandarin Chinese. They often spoke the language in public when they wanted to keep information away from the press and potential eavesdroppers."

https://www.languageconnections.com/blog/7-most-surprising-multilingual-u-presidents-in-u-s-history/