某地区大气中CO的浓度在标准状态时的浓度为0.050mL/m3 ,换算成mg/m3约为()。
A.0.0725
B.0.625
C.0.455
D.0.0625
参考答案:D
革兰阳性菌与革兰阴性菌细胞壁的共同成分是
A.肽聚糖
B.磷壁酸
C.脂多糖
D.外膜
E.类脂A
I really don't know ___________ about it. [ ]
A. what to do
B. how to do
C. to do what
D. how can I do