根据句意及首字母提示完成单词。 1. I sent my mother a m______ to tell her that I got to Beijing safely. 2. Why didn't you do your homework? Students are s______ to do their homework, you know. 3. When he got the ball, he quickly p______ it on to others. 4. Tom said to his mother,'Don't be m______ at me. I won't do it again.' 5. Remember to r______ the library books on time.