Hfo
abbr. heavy fuel oil 重（燃）油; high-frequency oscillator 高频振荡器
🗣️ 情景例句
I see you're feeling better already, Betty.
我看得出来你已经感觉好些了， Betty。
When did you take the examination?
你什么时候去参加考试？
Have you ever been to West Hill Farm?
你曾到过西山农场吗？