The committee for the class picnic party made careful plans for a beech party but they reckoned without a sudden change in the weather. 班級野餐委員會(huì )精心計劃了海灘交誼會(huì ),但是他們沒(méi)有料到天氣的突然變化。
Be on the watch for a sudden change in the patient's condition. 要密切注意病人病情可能突然變化。