简答题 Write on ANSWER SHEET THREE a note of about 50~60 words based on the following situation: Suppose you are Wang Xin. Your friend Mrs. Smith has invited you to her house to have a dinner this Wednesday. However, you have had a previous engagement for the same day. Write her a note politely declining her invitation and expressing your best wishes to her. Marks will be awarded for content, organization, grammar and appropriateness.