短語(yǔ)詞組短語(yǔ)when problems crop up 惹事;出現(xiàn)變故crop up on 在begin to crop up 露出苗頭problems may crop up 突然出現(xiàn)的問(wèn)題to crop up 蹦出來(lái)crop up here and there 層出不窮to begin to crop up 冒頭That crop up for air 爲(wèi)了空氣拔地而起;爲(wèi)了氛圍拔地而起new problems crop up unexpectedly 節(jié)外生枝 返回 crop up