罗-琴培养基用于培养结核分枝杆菌的作用有()
A.营养作用
B.鉴别作用
C.选择作用
D.含脂质生长因子,能刺激生长
E.有利于长期培养
参考答案:A, C, D, E
They discovered a large collection of old pots _______ Qin Dynasty, which are still _______ today.
A.dates from; very valuable
B.dating back to; of great value
C.dated back to; of much value
D.dating from; very value
食品生产企业建立食品原料、食品添加剂、食品相关产品进货查验记录制度的意义是什么?