In low-speed network，it is usually adequate to wait for congestion to occur and then react to it bytelling 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．In ATM network，a major tool for preventing (73) is (74) control．When a host wants a new virtual (75) ，it must describe the traffic to be offeredand the service expected．

（73）处填（）。

A．collision

B．congestion

C．drop

D．delay

7岁大女孩，胎龄26周出生，普遍发育落后，运动发育在4岁水平，曾有过数分钟的双目凝视，及不对称的上肢痉挛，既往治疗显示控制困难，需要两种抗癫痫药物才能控制，父母了解的信息是绝大部分有关失神发作随着年龄的增大而改善，且发育正常，其父母咨询他们的孩子是否会有同样好的预后，你的回答：（）

A.失神发作可以完全控制，可以正常发育

B.失神发作可以完全控制，发育落后

C.持续癫痫发作但发育最终正常

D.持续癫痫发作，持续发育延迟

E.癫痫部分缓解，发育正常