In low-speed network, it is usually adequate to wait for congestion to occur and then react to it by telling the source of packets to slow down. In high-speed networks, this approach often works poorly, because in the (71) between sending the notification and notification arriving at the source thousands of additional (72) may arrive．InATMnetwork，amajortoolfor preventing (73) is (74) control. When ahostwants a new virtual (75) , it must describe the traffic to be offered and the service expected.

A．interval

B．time

C．slot

D．delay

下述治疗方法在康复医学中不常用的是（）。

A.物理治疗

B.作业治疗

C.中国传统康复治疗

D.手术治疗

E.心理治疗