第1个回答 2010-05-04
Please let me know when you're available. I want to change the books.本回答被网友采纳
第2个回答 2010-05-04
口语化表达是:Please let me know if available,I wanna exchange the book.
第3个回答 2010-05-04
Please let me know when you are free,cause I want to come to change the book!
第4个回答 2010-05-04
Please let me know when you are free, i'd like to exchange the book.
第5个回答 2010-05-04
imform me when you are free ,i want to exchange the books