在空分装置中,蒸汽冷凝和液体蒸发的过程是两个相反的过程,但都是()
A.质到量变
B.质到质变
C.量到质变
参考答案:C
() students in Class 4 took park in that spring outing.
A. 48 all
B. 48 whole
C. All the 48
D. The whole 48
喹诺酮类是广谱抗生素,主要作用于细菌细胞的()。