牙套是什么啊?是不是金属冠之类的啊?安

皮圈用于关闭缝隙,调整小角度偏转的牙齿轴向.一般是将皮圈的一头至于相对固定端,一段挂于有缝隙的,或是偏斜的牙齿固定装置处.

解题思路：牙齿漂白剂应无毒，在口腔内反应后的产物无毒，无腐蚀性．

虽然都具有漂白性，但C1₂的水溶液有毒，HNO₃具有腐蚀性，Na₂O₂能与水剧烈反应且生成的氢氧化钠具有腐蚀性，双氧水还原产物是水，适合漂白牙齿．
故选B．

点评：
本题考点： 过氧化氢．

考点点评： 本题考查常见的漂白剂，难度不大，注意C12、HNO3、Na2O2、双氧水漂白性的区别．

wear the braces
注意 英语里的 戴 一律用 wea

at this thursday , i could take off my dental caps
finally . Taking it has been more than a year , actually , i can move it at augest ,but due to the carelessness that i forgot to disentangle the tegument at the last month , this led to the movement of one tooth , so had to put off the date two monthes later .

这句话不长,但翻译起来不简单
Of direct tapping and thread sheath,which is needed to this metal component?

teeth braces 牙套

解题思路：牙齿漂白剂应无毒，在口腔内反应后的产物无毒，无腐蚀性．

虽然都具有漂白性，但C1₂的水溶液有毒，HNO₃具有腐蚀性，Na₂O₂能与水剧烈反应且生成的氢氧化钠具有腐蚀性，双氧水还原产物是水，适合漂白牙齿．
故选B．

点评：
本题考点： 过氧化氢．

考点点评： 本题考查常见的漂白剂，难度不大，注意C12、HNO3、Na2O2、双氧水漂白性的区别．

if i had put on a tooth socket at my twelve or thirteen,my tooth would looks much better~

In my opinion,people teeth ache is the most painful thing.Yesterday I had molar,my teeth ache special,like a similar cavities than cavities Huanteng.Yes can not eat,bite.When I hungry when only watching.If you have not experienced,certainly do not know what kind.
机译

Her mother brought her to see the doctor and let her have braces.