下列常见的系统定义的异常中，属于主机网络故障异常的是（）。 A: Class Not Found Exception B: IOException C: File Not Found Exception D: Unknown Host Exceptio

智慧职教: 现有: 1. class Birds { 2. public static void main (String [] args) { 3. try { 4. throw new Exception () ; 5. } catch (Exception e) { 6. try { 7. throw new Exception () ; 8. } catch (Exceptio

A Convention about safety of life at sea was adopted in 1974 which included a new amendment procedure, according which an amendment shall enter into force（） A: after being accepted by more than two thirds of the Parties B: after being accepted by more than half of the Parties C: within a specified period of time with no objections D: within a specified period of time with no exceptio