Heliox
n. 氦氧混合气(含98%氦和2%氧,供潜水员在深水中维持呼吸用)
🗣️ 情景例句
How much notice of cancellation is necessary to get my deposit back?
想把定金拿回来，要提前多长时间通知你才行？
He didn't weep as he walked from the grave.
他从墓地走回来，并没有伤心流泪。
Education is one of the key words of our time.
教育是我们这个时代的关键词之一。