按“先进后出”原则组织数据的数据结构是______。
参考答案：栈 或 Stack
Sam said sorry to his mother , so she _________.
A．forgave his mistakes
B．forgave him of his mistakes
C．forgave him about his mistakes
D．forgave him for his mistakes
古代医家把医学称作是
A．医术
B．仁术
C．人术
D．技术
E．艺术
