Hfo
abbr. heavy fuel oil 重（燃）油; high-frequency oscillator 高频振荡器
🗣️ 情景例句
And a full night.
还有一整夜。
I feel guilty because I haven't written her lately.
因为我最近没给她写信，我感觉到有罪。
It is, in fact, a primitive type of calendar.
事实上是一种最原始的日历。