色素在包糖衣时主要用于()
A.打光
B.糖衣层
C.粉衣层
D.隔离层
E.有色糖衣层
参考答案:E
构成核酸的基本单位是()
A.磷酸戊糖
B.核苷
C.核苷酸
D.多核苷酸
E.脱氧核苷
Do you think that it is necessary to draw a distinction between acquisition and learning Why or why not