问题
单项选择题
主要用扭转力拔除的牙是（）
A.上颌第三磨牙
B.下颌中切牙
C.上颌中切牙
D.上颌前磨牙
E.下颌前磨牙
答案
参考答案：C
解析：上颌第三磨牙一般有三个牙根，两个颊根、一个腭根，且呈现分叉，拔除时不能用扭转力。下颌中切牙、上颌前磨牙以及下颌前磨牙均为变形根，只能通过唇（颊）舌向的摇动拔除。上颌中切牙的牙根呈圆锥形，可稍加扭转力拔出，故选C。
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主要用扭转力拔除的牙是（）
A.上颌第三磨牙
B.下颌中切牙
C.上颌中切牙
D.上颌前磨牙
E.下颌前磨牙
参考答案：C
解析：上颌第三磨牙一般有三个牙根，两个颊根、一个腭根，且呈现分叉，拔除时不能用扭转力。下颌中切牙、上颌前磨牙以及下颌前磨牙均为变形根，只能通过唇（颊）舌向的摇动拔除。上颌中切牙的牙根呈圆锥形，可稍加扭转力拔出，故选C。
| 阅读理解。 |
| Most children don't want their parents to go to their schools and they don't like parent-teacher meetings. They are afraid of their parents. But sometimes they do not do what their parents tell them to do. When this happens, a parent tries to help the child to do the right thing. When this does not work, the parent usually punishes the child. There are many things that a parent can do. One thing that people have done is to spank (打屁股) the child. When a parent spanks a child, he will use his hand or something hard to strike the child on the bottom. The parents want to show their children that they have done something wrong. One problem with spanking is that it teaches the child to hit someone when they do not like what the other person is doing. Another problem with spanking is that the parent is usually angry and can hit the child too hard. Sometimes parents will use spanking for everything and not try other ways to get the child to do the right thing. Many parents are not sure of what to do instead of spanking. Some people think that spanking is okay. Some think that the law lets them do it. The courts (法院) say that parents have the right to teach their children how to behave. Other things should be tried before a parent decides to spank a child. Taking a more child-friendly way can help as well. Giving a child more than one choice is another thing that can be tried. |
| 1. According to the passage, one thing that parents usually do to punish their children is to _______. |
[ ] |
| A. strike them on the bottom B. try to help them do the right thing C. teach them what to do D. take them to court |
| 2. Most children are afraid of their parents, _______. |
[ ] |
| A. so they don't like their parents B. so they never do something bad C. but sometimes they do what their parents tell them not to do D. but they try to help their parents |
| 3. Which of the following is NOT the problem caused by spanking? |
[ ] |
| A. It teaches the child to hit others when they offend (冒犯) him or her. B. The parent may get angry and hit the child too hard. C. Sometimes parents may use spanking for everything. D. It makes parents try other ways to make the child do right. |
| 4. What is the writer's attitude towards spanking? |
[ ] |
| A. He agrees with it. B. He is interested it. C. He doesn't care about it. D. He is against it. |
| 5. From this passage, we can know that _______. |
[ ] |
| A. Good children always do the right thing B. Right ways should be used when parents try to teach their children a lesson C. Parents should not punish their children D. parents should tell children want to do |