1 replace sb/sth (as/with sb/sth) to take the place of sb/sth; to use sb/sth in place of another person or thing 取代；代替: Teachers will never be replaced by computers in the classroom. 在课堂里，老师永远也不会被计算机所替代。

2 replace sb/sth (with sb/sth) to exchange sb/sth for sb/sth that is better or newer 更换；换成好的或新的；调换: We will replace any goods that are damaged. 我们会更换任何损坏的货物。

3 to put sth back in the place where it was before 放回原处: Please replace the books on the shelves when you have finished with them. 那些书看完后，请放回书架上。 ☞ Put back is more common and less formal. put back较常用，多用于非正式场合。