单项选择题 标准库os中的函数remove()可以删除带有只读属性的文件。 A、正确 B、错误

单项选择题 具有糜棱结构的变质岩属于（    ）变质岩。 A、区域 B、接触 C、动力 D、气液

单项选择题 Why was it expensive to send a telegraph? A、Because it takes a long time. B、Because it is fast. C、Because you should pay for each character(按字付费). D、Because it sends a lot of messages once a time