停发法
参考答案：
又称空闲重发请求，规定发送方每发送一帧后就要停下来等待接收方的确认返回，仅当发送方收到接收方的正确接收确认后再发送下一帧。
58. --- Do you still remember when we went to the Summer Palace?
--- I can’t remember it well, but it _____ sometime last July.
A．must have been
B．might be
C．could be
D．might have been
黄体酮
A．四氮唑比色法B．铁-酚试剂比色法C．异烟肼比色法D．气相色谱法E．碘量法下列药物可采用的含量测定方法为
