There is a large, square white envelope in the mail for you on a June morning. You open it eagerly and shriek with sudden surprise, "Another marriage! I haven't seen her since our sophomore year in college. I wonder what kind of man she is marrying?" Then, after a moment's thought, "Oh, dear! What shall I wear? I haven't a decent rag in the house! - Shall I answer an invitation to a church wedding? Must I send a present?"