一封书信包括有3个部分:引言,目的和结束语.其中最主要的部分是目的.在这部分中你必须说明为什么要写此信.请按照以下两段引言的思路,各写出50个词左右的目的:1.You will be surprised to hear that your uncle Peter has unexpectedly returned from South America.He is staying with us at present and I konw that he would very much like to see you.2.I have some wonderful news for you.I have at last managed to get two tickets for the Cup Final.