小题1:A
小题2:D
小题3:C
小题4:B
文章介绍了冰岛的火山爆发导致欧洲飞机改变航道，并介绍这一火山的相关情况。
小题1:细节题。由第二段的第一行What makes Grimsvotn different is that it lies under a huge glacierof ice up to 12 maters thick.可知它有别于其是位于巨大冰川之下，， A.
小题2:D .细节理解题。由第二段的This layer of water puts pressure on the volcano, keeping it stable,可知水的压力让它稳定D。。。。
小题3:C细节理解题。由最后两段可以看出由最后两段可以看出由最后两段可以看出由最后两段可以看出A,B,D都，The eruption has also caused problems for animals in Iceland .Farmers are keeping their animals inside to stop them from eating ash- covered grass to the sharp object. C正确。
小题4:B。推理判断题。通读全文可知是一篇新闻报道通读全文可知是一篇新闻报道，选B。