A. less moisture than cold air B. more moisture than cold air C. the same amount of moisture as cold air D. moisture independent of air temperature
A. 15 B. 17 C. 19 D. 21
A. 由一层膜包围而成 B. 与蛋白质的合成有关 C. 与蛋白质的加工有关 D. 由小泡、扁平囊、大泡组成