畜、禽肉中下列哪些维生素含量较高（）
A.维生素A和维生素D
B.维生素C
C.维生素B1
D.维生素B2
E.尼克酸
参考答案：A
— He _____ the English-Chinese dictionary for about twenty years, but it is still new.
— What a careful man! [ ]
A. has bought
B. has borrowed
C. has had
利用工作叶轮的旋转运动来输送液体的是（）
A、容积泵
B、叶片泵
C、螺旋泵
D、液压泵
