1.The supposedly-exceptional circumstance now happens once a week, on average.
现在这种超出预想的情况平均每周发生一次。
2.When your application encounters an exceptional circumstance, such as a pision by zero or low memory warning, an exception is generated.
在应用程序遇到异常情况（如被零除情况或内存不足警告）时，就会产生异常。