关于腺泡的描述,不正确的是
A. 是唾液腺的分泌单位
B. 与最细小的导管相连
C. 由单层锥体形腺泡围绕而成
D. 中央有一腺泡腔
E. 腺细胞和基底膜外有肌上皮细胞包绕
平滑面龋的病损形态是
A. 烧瓶状,口大底小
B. 烧瓶状,口小底大
C. 三角形,底位于釉质表面
D. 三角形,底位于釉牙本质界(窝沟龋)
E. 浅碟状,口大底浅
釉质龋暗层的孔隙容积占釉质体积的
A. 0.1%
B. 1%
C. 2~4%
D. 5%
E. 25%
Listen to the following dialogue and answer the questions that follow. How many people were involved in the conversation?____________ people. (空格处请填入英文数字, 并注意句首字母大小写的要求。)