v.不能;
例句:
He was vacationing and couldn't be reached for comment.
他当时正在度假,无法联系到他征求意见。
I couldn't remember ever having felt so safe and secure.
我从未有过如此安全的感觉。
He rubbed and rubbed but couldn't seem to get clean.
他擦了又擦,可就是擦不干净。