填空题 Northern Europeans will not forget the name Eyjafjallajokull (埃亚菲亚德拉冰盖) in a hurry, even if they may have trouble pronouncing it. Monday April 19th marked a fifth day of jet-free skies over a huge swathe of the continent as a result of the eruption of the Icelandic volcano, which began pumping large quantities of ash into the sky last Wednesday. (41) ______.
Demonstrating the unpredictability of volcanic eruptions, Britain's National Air Traffic Service said on Monday afternoon that airspace in Scotland and parts of northern England would reopen on Tuesday morning, and sounded optimistic that the rest of Britain would be cleared for flying later in the day; hut later switched to a more cautious tone as a new ash cloud began spreading. Earlier, Norway, Sweden and Finland had allowed a few mainly domestic flights to operate.
The civil-aviation authorities had come under strong pressure from European airlines, several of whom had conducted successful test flights in the supposed danger zone. However, the engines of a Finnish military jet did suffer considerable damage as a result of breathing in the ash.
By late on Monday night there was still no clear answer as to how long the disruption might last. (42) ______ Furthermore, there is no way of telling what concentration of ash the test aircraft were flying through. The best source of information for the moment is a theoretical model of where the cloud might be, taking into account the prevailing wind and other weather conditions. One interesting wrinkle is that studies of natural disasters tend to be paid for by insurance companies. As volcano eruption is deemed to be an uninsurable (不可予以保险的) risk, there are few studies to turn to.
(43) ______ The industry body reckons that its members have been losing $ 200m a day as a result of the shut-down. On Monday British Airways said that it and other European airlines had asked for cash from the EU in compensation for the losses suffered because of the closure of airspace, citing the bailout offered to American airlines in the wake of the September 11th 2001 terror attacks. IATA reckons the situation for Europe's airlines is even worse than then.
(44) ______ If meteorologists and vulcanologists developed a dynamic model of the ash cloud's progress, it might be possible to keep more airports open, and to reroute planes to get passengers moving again. Wind patterns could change at any time and some reckon that they might do so by the end of the week. If the ash cloud were to drift in another direction flights could be sent around or above it. But when it sits over Europe's biggest airports, that is all but impossible. And while there remains any uncertainty, passengers may decide not to make trips in case the temporary respite reverses along with the wind. stranding them far from home.
(45) ______ Some fear that they could be in for a long wait. Icelandic volcanic activity has been low for some time. Eyjafjallajokull is particularly prone to producing the fine ash that has caused the current mayhem.
So far, aside from airlines and air travellers, the impact has been limited. But as the shutdown continues Europe's fragile economies will suffer as tourists fail to arrive, meetings are cancelled and businesses with supply chains that rely on air freight nervously watch stocks running down.

[A] This uncertainty has led the International Air Transport Association (IATA) to plead on behalf of its members for Europe's government to rethink policy on shutting airspace.
[B] If the eruption were to worsen again, there are several ways that the damage wrought by the volcano might be mitigated.
[C] That fine volcanic ash could pose a risk to jet engines, which have broken down in the past' after exposure to similar volcanic material. Many of Europe's busiest airports remained out of action.
[D] Some air freight might take to the road or water—98% of the world's trade is already carried by ship. And plenty of the world's container vessels are sitting idly waiting for the world economy to pick up after the recent recession in the rich world.
[E] For one thing, the European Aviation Safety Agency says that there is currently no consensus as to what is an acceptable level of ash in the atmosphere.
[F] Some airlines were offering little compensation, leaving cash-strapped travelers to turn a number of international airports into impromptu emergency shelters. Across Europe, meanwhile, authorities were weighing cancellations of championship soccer matches and heads of state were altering travel plans.
[G] Even if the volcano stopped emitting ash immediately, it might take two or more weeks before airlines could restore their schedules, with planes and crew stuck around the globe along with their passengers.