Pehameter
[化] pH計(jì)
??? 情景例句
When you understand the cultural background, you can better use the language.
當(dāng)你了解了文化背景，你就能更好地運(yùn)用語言。
What a great deal!
真劃算。
In 1929, three years after his flight over the North Pole, the American explorer, R.E.Byrd, successfully flew over the South Pole for the first time.
美國探險(xiǎn)家 R。伯德在飛越北極3年之后，于1929年第一次飛越了南極。