standard matter的用法和樣例：
例句
- The two gaseous Reference Materials, Carbon dioxide in nitrogen and methane in air, belong to standard mixed gases.
氮中二氧化碳和空氣中甲烷氣體標準物質(zhì)屬于標準混合氣。 - Their pureness deterimined in methods of two different priciples and conformed to the technical norm of first grade military standard substance.
四種標準物質(zhì)采用兩種不同方法定值，結果均達到一級軍用標準物質(zhì)要求。
