某钢厂计划每月出钢2800吨，上月完成了原计划的135%，那么上月出钢多少吨
A．3500
B．3650
C．3880
D．3780
参考答案：D
—How long have you been away from your hometown?
—______two years ago. [ ]
A. Since
B. For
C. In
D. From
什么是比热？其值的大小体现了物质的什么性能？
