Hfo
abbr. heavy fuel oil 重（燃）油; high-frequency oscillator 高频振荡器
🗣️ 情景例句
Now let's head off for the city and the university club.
现在让我们进城去， 到大学俱乐部。
It's the most up-to-date in the industry.
这是同业中最新型的。
A few days later about 140 black people were taken and put on a tall sailing ship waiting off the coast.
几天以后，大约140名黑人被带到一艘停靠在海岸边的大帆船上。