1.9965四舍五入到千分位是______．
1.9965≈1.997；
故答案为：1.997．
龙胆、防风、白薇、丹参等药材净选加工时应除去（）
A.去残茎
B.去皮壳
C.去心
D.去核
E.去芦
Which one of the following anatomy should not appear on the periapical radiograph of the lower central incisor
A．genial tubercles
B． mental foramen
C． nutrient canals
D．inferior border of the mandible
