单项选择题 根据《药品召回管理办法》药品生产企业作出药品召回决定后，应在72小时内通知有关药品经营企业、使用单位停止销售和使用的是（）

单项选择题 听力原文：M: How long have you been working in the laboratory?W: For almost three years, ever since I got my degree.M: Your bachelor's?W: No, my master's. I didn't try to get a job until I had my master's degree.M: What kind of research do you do? Are you trying to develop new products or something like that?W: No, that's clone by another group in the lab. The group I'm with is doing basic research.How long have the woman been working in the lab?A．Four years.B．Just three years.C．Almost three years.

单项选择题 设抛物线y2=8x的焦点为F，点P在此抛物线上且横坐标为2，则|PF|等于（）