Hfo
abbr. heavy fuel oil 重（燃）油; high-frequency oscillator 高頻振蕩器
??? 情景例句
Andy, oh my God. I can't believe it. What are you doing here? I thought you're in Singapore.
安迪，我的天，竟然在這里遇見你。你在這里干什么？我以為你在新加坡。
How much does the elephant weight?
這個大象有多重？
He repaired his house.
他修理了他的房子。