搜题请搜索小程序“爱下问搜题”
问题 单项选择题 A1/A2型题

下列关于前牙反早期治疗原则的说法，正确的是（）

A.乳前牙反，反覆浅者：可采用调磨法，即调磨下切牙切缘的唇侧部分、上切牙切缘的舌侧部分，使上、下前牙解除反牙锁结关系

B.乳前牙反，反覆中度者：可选用上颌垫式活动矫治器附双曲舌簧推上前牙向唇侧并后退下颌

C.乳前牙反，反覆深者：反覆深的患者可以设计下颌联冠式斜面导板

D.反覆盖过大的乳前牙反患儿，可先戴头帽、颏兜后移下颌并抑制下颌骨的生长，待反覆盖减小后，再视反覆的深度选择上述口内矫治器进行矫治

E.A、B、C、D均正确

答案

参考答案：E

阅读理解
阅读理解。
     Have you ever rubbed your hands together when they get cold? Why do we do that? We do that for
friction. Friction happens when two things that aren't very smooth rub together to make heat energy. The
faster you rub two things together, the more friction (and heat) you can make. Let's discover friction!
WHAT YOU'LL NEED:
      ● Soap     ● Water    ● Your hands!
WHAT TO DO:
     1. Make sure your hands are dry.
     2. Rub your hands together until you feel the heat of your hands.
     3. Now, use soap and water to get your hands very slippery (滑的).
     4. Try to make friction happen while your hands are slippery.
     5. Please write down what has happened.
LET'S TALK!
     Friction is an energy that happens when two things rub together. When friction happens,
it makes heat! When your hands are slippery, they won't make very much friction and your
hands won't get so hot.
DID YOU KNOW? 
     1. Friction happens when you stop your fast running bike.
     2. Ancient people made fires by rubbing two pieces of wood together. Friction happened
though they didn't know it. 
_________    
     Friction is everywhere. Have you ever noticed situations where friction is happening?
If not, ask your parents to take you out in a car. If it is not too hot, touch the tires (轮胎)
of the car before and after a short drive to see how much warmer they get from friction.
1. You'd better make your hands ________ to get heat when you rub them.
A. slippery
B. dry
C. wet
D. smooth
2. What does the word "friction" in this text mean in Chinese?
A. 摩擦
B. 冷却
C. 膨胀
D. 震动
3. ________ is NOT an example of friction.
A. Bike riding
B. Car driving
C. Hands rubbing
D. Friction discovering
4. What's the last column (栏目)?
A. THINK IT OVER!
B. WHAT HAPPENED?
C. EVERYDAY ACTION:
D. WORK WITH PARENTS!
5. This text is most probably ________.
A. a science report
B. a car advertisement
C. a rubbing introduction
D. a chemistry programme
查看答案
单项选择题

锅炉中属于低温受热面的是（）。

A.过热器

B.省煤器

C.再热器

D.水冷壁
查看答案