由于不同物质的性质不同,其热传导的能力是相同的。
参考答案:错
-Why are you watching a football match?
-__________[ ]
A. It's exciting.
B. I have a football.
C. I'm at home.
D. I watch football matches at night.
夹紧力作用点应落在工件刚性最好的部位上。