牙防指导组派出一科研小组到某氟牙症流行地区调查流行状况及其影_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题单项选择题

牙防指导组派出一科研小组到某氟牙症流行地区调查流行状况及其影响因素。根据研究计划，他们进行了以下工作

对一位外地转学来的学生检查时，上前牙表面有数个不对称白垩色斑，边界清楚，在强光下垂直观察不明显，而切线方向观察清楚，他们诊断为（）。

A．四环素牙

B．非氟性斑

C．色素附着

D．脱矿性斑

E．釉质发育不全

答案

参考答案：B

填空题

从方框中选择适当的词语填空。

have a look at, at a very good price, on sale,
in blue, I'm sorry, how much, buy…from,
in all colors, come down to, sells…to…

1. The boy __________ is my brother.
2. This shop has sweaters __________.
3. Boys can __________ T-shirts __________ this shop.
4. Please __________ my home and have dinner with us.
5. We have shoes __________.
6. This store __________ school things __________ the students.
7. Can I __________ your family photo?
8. The white pants are _____________ for $20.
9. —What time is it? —Oh, __________. I don't have a watch.
10.—__________ are the red socks? —They are $5.

填空题

从放热介质中吸收热量并传递给受热介质的表面，称为（）。