分拣是把货物按不同品种、不同的地点和单位分配到所设置的场所的一种搬运过程。
参考答案：对
_____ have an internal clock that controls the beating of our heart, and the _____ of our breathing. [ ]
A. Human being; steps
B. Humans; pace
C. Human beings; steps
D. Man; pace
呼吸道黏膜杯状细胞和黏液腺每日分泌黏液量为（）
A.5ml
B.1Oml
C.20ml
D.50ml
E.1OOml
