仅当事故情况下使用,工作场所内备用照明的照度(工作面上)不宜低于该场所一般照明照度的( )。
A.5%
B.10%
C.15%
D.20%
参考答案:A
—Can I have some more ice cream, Mum?
—Sorry. There is ________ left in the fridge. [ ]
A. none
B. nothing
C. no one
D. anything
简述髓内外病变的鉴别诊断。