钢中碳的含量超过1．00％时，钢材的性能表现为（ ）。
A．塑性大
B．强度下降
C．硬度大
D．易于加工
参考答案：B
－_____ leave at the end of this month.
－I don't think you should do that until _____ another job. [ ]
A. I'm going to; you'd found
B. I'm going to; you've found
C. I'll; you'll find
D. I'll; you'd find
制冷的方法有几类
