a sudden change

• 意外变故

a sudden change的用法和样例：

例句

1. The committee for the class picnic party made careful plans for a beech party but they reckoned without a sudden change in the weather.
   班级野餐委员会精心计划了海滩交谊会，但是他们没有料到天气的突然变化。
2. 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变化。