Elinvar is a trademark for a kind of nickel-chromium steel used for watch springs because its elasticity is constant over a wide range of temperatures.是什么意思_Elinvar is a trademark for a kind of nickel-chromium steel used for watch springs because its elasticity is constant over a wide range of temperatures.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句