单个矿块的表示方法一般可取()个相互垂直方向尺寸平均值来表示。
A.2
B.3
C.4
参考答案:B
It is hard for people in the country to believe that the minister could survive in such ________ weather conditions.
A.severe
B.obvious
C.positive
D.sceptical
下列各项中可以作为记账依据的会计凭证是()。
A.对账单
B.请购单
C.购销合同
D.报销单据