1. 恒牙：7~12岁,乳牙先后脱落;恒牙(permanent teeth) 28~32个,自6岁起,渐次与乳牙更换,至12岁前后除第三磨牙(智齿)外,全部萌出,第三磨牙一般在20岁以后萌 你从小缺钙,长大不缺爱,因为有小弟在支持你.
2. 恒齿：约到两岁半左右长齐...另一套叫做恒齿(permanent teeth) 全部萌出(含智齿)有32颗...从进入学龄期大约六岁开始 乳牙逐渐脱落 换上以后再也不更换的牙齿
3. 口腔：消化系统 mouth cavity | 口腔 permanent teeth | 恒牙 deciduous teeth
4. 恒齿,恒牙：permanent tangible property ==> 耐久性有形资产 | permanent teeth ==> 恒齿,恒牙 | permanent testing ==> 长期试验
1. Between four to eight months, puppies shed all their deciduous teeth and grow a new set of permanent teeth.