问题
单项选择题
彻底去除牙石主要是因为牙石
A．可直接引起牙周袋
B．可引起牙龈退缩
C．内含各种炎症因子和细菌毒素
D．是菌斑滞留堆积的部位
E．以上均是
答案
参考答案：D
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彻底去除牙石主要是因为牙石
A．可直接引起牙周袋
B．可引起牙龈退缩
C．内含各种炎症因子和细菌毒素
D．是菌斑滞留堆积的部位
E．以上均是
参考答案：D
| 短文填空，阅读下面的对话，用方框中的词或词组填空，每个词或词组只能用一次。 | |
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| A: Hello, Jack. Come here, please. Do you know the 1 in school? B: Yes, Mr. Brown. First we 2 wear hats in school. A: That’s right. B: Don’t arrive late for 3 . A: Good. What 4 ? B: Do we 5 eat in the dining hall? A: No, you don’t. You 6 eat outside. B: And we can 7 music outside, but not in the classrooms. A: Yes. B: We can’t 8 anyone. A: Yes. You should be friendly. Can we 9 in the hallways, little boy? B: No. It’s dangerous. A: You’re right, my little boy. Then why did you run in the hallways? B: Sorry, Mr. Brown. I won’t 10 school rules again. |