用二阶系统作测量装置时，为获得较宽的工作频率范围，则系统的阻尼比应接近0、707。（）
参考答案：对
— Mum，I really think Dad should have a break and get relaxed．
—Yes．He too long．
A．read
B．had read
C．has been reading
D．is reading
A．5A
B．5A
C．3.5A
D．3.5A
