How does weighted random early detection （WRED） prevent packet loss？（） ["increases link capacity","increases buffer space to accommodate bursts of traffic from delay-sensitive applications","provides prioritized forwarding for drop-sensitive applications","drop lower priority packets before congestion occurs","separates traffic into as many as 64 queues that can be uniquely prioritized"]
2001年7月13日北京申办2008奥运会成功，可是距此一百年前（1901年），西方给中国送来了一份令人不堪忍受的新世纪贺礼是（） ["八国联军侵华战争","《辛丑条约》","洗劫北京城","血腥镇压义和团运动"]
广告视觉流程设计中最活泼最有力的因素是（） ["节奏","韵律","视线诱导媒介","色彩"]
急性心肌梗塞发病早期（6小时内），最有积极有效的限制梗塞面积措施是：（） ["抗凝治疗","抗血小板治疗","尽快开通梗死血管","绝对卧床休息","静脉应用硝酸甘油"]
流线
继电保护的操作电源有几种，基本结构如何，有什么优缺点？操作机构的用途是什么，怎样分类？
