回答 64 ~ 67 题：A volcanlc ctuption in iceland has sent ash zcross northern Europe .Airlines have Stopped or changed the flights across the Allantic Ocean , leaving hundrede of passengets stuck in aipports.Grimsvotn is one of the largest and most active volcadoes in Europe. What makes Grimsvom different is that it lies under a huge glacier(冰川) of ice up to 12 maters thick. The hot volcano heats up the ice above it, which then forms a layer(层)of water between the glacier and the volcano This layer of water puts pressure on the volcano, keeping it stable, As the water flows out from under the glacier, the pressure lifts. The lava(岩浆) from the volcam then comes up to the surface. This is exactly what happened today.Now, airlines have to make changes to their flights so as not to fly through the clouds of volcanic ash. According to KLM.one of Europe’s biggest airlines,airplanes cannot go under the cloud or over it. Going through the cloud can result in ash getting stuck in the airplane’s engines,causing damage to the plane.The eruption has also caused problems for animals in Iceland. The voicane left ash and sharp. Glass-like rocks all over the countryside. Farmers are keeping their animnls inside to stop them from eating ash- covered grass to the sharp object.第9题：What makes Grimsvotn different from other volcanoes?