读下图漫画，据此回答题。漫画告诉我们（   ）。

根据句义完成句中已给出首字母的单词。将每个完整的单词写在各小题右边的横线上
 Don't  w____ about your dog. I believe it can find the way back.
 My sister will take her f____  examination next week, and then she will leave university.
You have left dirty m____  on the door. Clean them up.
The teacher often asks the students to keep away from the s____  they meet.
You should leave i____ . The bus is leaving soon.

如图，点A（m，6）、B（n，1）在反比例函数图象上，AD⊥x轴于点D，BC⊥x轴于点C，DC=5．

 钠及其化合物是中学化学学习和研究的重要内容．