Definition
to occur or become noticeable without warning
突然出現；意外發生；冒出
Many unexpected problems cropped up in our plans.
我們的計劃中突然出現了很多意外的問題。
Several important topics cropped up during the meeting.
在會議期間突然出現了幾個重要話題。
A new opportunity cropped up when I least expected it.
當我最不期待的時候，突然出現了一個新機會。