根据首字母及汉语提示，完成下列单词的拼写，使句意明确，语言通顺。
1. It is i_________ (重要的) for you to keep healthy.
2. He r_________ (收到了) a story-book on his last birthday.
3. We shouldn't throw rubbish e_________ (到处) to protect environment.
4. A_______ (四月) is the fourth month of a year.
5. "Help y_________ (自便) to some fish." Mum said to my friends.