Unavailability
[计] 无效性, 不可用性
🗣️ 情景例句
Chairman Mao said it is necessary to drill as much as possible.
毛主席说，反复操练是非常必要的。
I'm going to lend her two cans.
我要借给她两罐。
He asked very politely, Excuse me, have you got any books about the moon and the stars?
“请问，你有关于月亮和星星的书吗？”