热胀冷缩（Heat expands,Cold contracts）
金属热胀冷缩：
Metal expands with heat and contracts with cold.
一般来说,固体热胀冷缩：
As a general rule,solids expand as the temperature increases and contract when they are cooled
热胀冷缩是所有物质的共性.It is a common property of any matter that is expanded when it is heated and it contracts when cooled.
即：任何物质,如果遇到热,它就会膨胀,如果遇到冷,它就会收缩,这是共性
热胀冷缩是一种自然形成的东西,热就膨胀,冷就缩小.
热膨胀(Thermal Expansion)