Backfills
回填（挖掘的洞穴）( backfill的第三人称单数 )
🗣️ 情景例句
Does this car have good fuel economy?
这种车省油吗？
How do you do?
你好
They then knew that they had discovered the cause of the fire.
这时调查人员知道他们找到了发生火灾的原因了。