菜刀在磨石上磨来磨去,会产生热,温度升得很高。如果不加水就这么干磨,时间一长,菜刀就不硬了,切硬东西费劲儿。磨力的时候加点儿水,水把磨刀时产生的热带走一些,磨好了的刀不仅好使,也不容易损坏。
JBTALKS.CC |联系我们 |隐私政策 |Share
GMT+8, 2026-1-1 12:18 AM , Processed in 0.107041 second(s), 24 queries .
Powered by Discuz! X2.5 © 2001-2012 Comsenz Inc.
本论坛言论纯属发表者个人意见,与本论坛立场无关
Copyright © 2003-2012 JBTALKS.CC All Rights Reserved
Dedicated Server powered by iCore Technology Sdn. Bhd.