9.
阅读下面材料,在空白处填入适当的内容(1个单词)或括号内单词的正确形式。
We all know teeth are important to our life. We celebrate National Teeth-Loving Day September 20th.
Do you know the life cycle of (tooth) in your mouth? Children under six (year) old have 20 baby teeth. From 6 to 13, people lose (they) baby teeth one by one. Now permanent teeth(恒牙) begin (grow).
Between the ages of 17 and 25, some people grow wisdom teeth(智齿).
Do you know to keep our teeth strong and healthy? Let's look at the following tips.
What we can do:
※ Brush your teeth at least twice a day: in the s time morning and bedtime.
※ Brush for at least two or three minutes every time.
※ (use) dental floss(牙线) for your teeth to make them cleaner.
※Get a new toothbrush every three months.
What we can't do:
※Don't eat too (many) candy and sweet food, or don't drink too much soda.
※Don't eat very hard food, That can hurt your teeth.
※Teeth are important to everyone. Healthy teeth help us eat food to let us grow.
※They help us speak clearly. And yes, they help us look good.