道路运输从业人员诚信考核和计分考核周期为（），从初次领取从业资格证件之日起计算。
A、6个月
B、12个月
C、24个月
参考答案：B
-- I’m sorry we ________ all the educational CD-ROMs. Can you come next week?
-- Please call me as soon as the latest one _________.
A．have sold well, comes out
B．have sold out, comes out
C．have sold well, is come out
D．have sold out, is come out
金属材料与热处理是一门研究金属材料的成分、组织、热处理与金属材料性能之间的关系和变化规律的学科。
