[单项选择]Nearly 2, 000 feet in the air, above where the Mississippi River flows into the Gulf of Mexico, the approaching storm is in full view; millions of gallons of wind-swept crude oil, in streaks that arc not black but orange, red and brown. It’s easier to grasp the severity of the crisis unraveling in the Gulf of Mexico when you have an airborne perspective of the oil that is barreling toward the shore. A group of environmentalists, reporters and bayou defenders went up on a small plane for a tour of the coast. "I’ll show you the Cajun Bahamas, "the pilot, Lyle Panepinto, said. Minutes later, he pushed the plane from 1, 100 feet to 2, 000 feet above the water, out toward the Chandeleur Islands, between Louisiana and Mississippi. Earlier this week, scientists collected samples of oil from the islands. "It might be no more, when this is over with, " Panepinto said of the islands, home to several private fishing camps.Booms placed around a tiny island are of little use because
[A] they c

某施工单位承接的某高速公路合同段中有一座公路隧道。该隧道为单洞双向行驶的四车道深埋隧道，设计净高6.9m，净宽20m，进口桩号为K9+868，出口桩号为K13+218。根据地质勘察报告，隧道穿越的地层有：砂岩、页岩、泥灰岩，其中K10+000～K11+500段还分布有冲刷煤屑、瓦斯包体和含水瓦斯包体，岩层节理及裂隙发育。设计要求采用新奥法施工、分部开挖和复合式衬砌，隧道施工监控量测实施了洞内、外观察、周边位移监控。
事件1：施工单位采用双向掘进，对水、电、路、通风等设施进行统一安排，并在正式掘进前完成。通风方式采用大功率通风机将新鲜空气采用风管压送到掌子面，然后将废气从里往外挤出。通风机采用轴流式，其额定风量为2250m／min，风压为6kPa，发电机功率为2×115kW。风管与风机相匹配，选配1500mm（压入）和1000（吸出）的强力橡胶软管，每节长10m，软风管接头方式为双反边拉链式接头，安装方便、密封性能好。
事件2：隧道施工时的通风，设专人管理。要求做到：保证每人每分钟得到1m的新鲜空气；隧道内的空气成分每两月至少取样分析一次。事件3：某日早上7时.1名工人进洞启动设备，产生火花，导致隧道发生瓦斯爆炸，该名工人罹难，所幸洞内当时没有其他作业人员，造成损失约320万元。土建施工完成后，项目部按要求进行了照明、供配电设施与交通标志、防撞设施、里程标、百米标等的施工。照明控制系统由分中心监控工作站、A、亮度检测器和照明配电回路（箱）的接口电路构成。该隧道原设计采用射流式通风方式，经多方论证后，难以满足该隧道的通风质量要求，拟变更为竖井排风式通风，并按相关程序完成了设计变更。

1.依据现行的《生产安全事故报告和调查处理条例》，判断该事故等级。
2.背景中隧道按长度分属于哪类隧道？按《公路工程设计变更管理办法》，背景中设计变更属于哪一类变更？说明理由。

Euthanasia has been a topic of controversy in Europe since at least 1936. On an average of six times a day, a doctor in Holland practices "active" euthanasia: (1) administering a lethal drug to a (2) ill patient who has asked to be relieved (3) suffering. Twenty times a day, life prolonging treatment is withheld or withdrawn (4) there is no hope that it can (5) an ultimate cure. "Active" euthanasia remains a crime on the Dutch statute books, punishable (6) 12 years in prison. But a series of court cases over the past 15 years has made it clear that a competent physician who (7) it out will not be prosecuted.
Euthanasia, often called "mercy killing", is a crime everywhere in Western Europe. (8) more and more doctors and nurses in Britain, Germany, Holland and elsewhere readily (9) to practicing it, most often in the "passive" form of withholding or withdrawing (10) A. against
B. off
C. of
D. out of