过滤字节输出流都是【 】抽象类的子类。
参考答案：FilterOutputStream
解析：主要熟悉java.io包中的几个输入／输出流。
Our aim is to select the best person for the job, _______ they are from.
A．wherever
B．however
C．whatever
D．whenever
按动作原理时间继电器分那几种
