物体上没有活的微生物存在叫( )。
A．灭菌
B．无菌
C．消毒
D．防腐
参考答案：B
— How could you be so impolite when there were so many guests in the party?
— _____________. [ ]
A. Nothing serious
B. Never again
C. Never mind
D. Not enough
对于实性癌的描述，下述哪个是不正确的
A．癌细胞的异型性大
B．又叫实体癌或单纯癌
C．是一种低分化腺癌
D．指肿瘤无囊性变，呈实体状
