Unavail
无效的,无用的
🗣️ 情景例句
Be careful, I think the neighbors have been spying on us.
小心点，我觉得我们邻居一直在窥视我们。
A useful trade is a mine of gold.
一样有用的手艺是取之不尽的财富。
What about you?
你呢？