prep. On; -- used in all the senses of that word, with which it
is interchangeable.
prep. 在...之上, 迫近, 紧接着
1. She placed the book upon the table.
她把书放在桌子上。
2. Upon finishing his homework, he went out to play.
完成作业后,他出去玩。
3. The decision was made upon careful consideration.
这个决定是在仔细考虑后做出的。