2．Greenland is Shrinking at Surprising Rate
A new study shows one of the largest glaciers in Greenland is becoming smaller and speeding to the sea faster than scientists expected．If it continues，Greenland itself could become much smaller during this century and global seas could rise as much as 3 feet．
The rates of change that we're noticing are much higher than expected．If these rates continue，it is not unlikely that Greenland could shrink by several tens of percent this century．However，it's not known how quickly this coastal response of the Greenland ice sheet melting will have an effect on the vast inland ice．
Greenland is the world's largest island，covering an area more than three times the size of Texas．Some 81 percent of it is covered by ice，and there are many glaciers．Glaciers are like slow-moving rivers of ice．Where a glacier meets the sea，its weight keeps it firmly resting on the bottom．A glacier's front is the point where the water is deep enough that the glacier floats．
Since the 1970s，the front of Helheim stayed in the same place．Then it began melting rapidly，moving back 4.5 miles from 2001 through this past summer．It has also grown thinner，from top to bottom，by more than 130 feet since 2001．And over these past four years，its trip to the sea has sped up from about 70 feet per day to nearly 110．
The melting is driven by a warmer climate．Temperatures in Greenland have risen more than five degrees Fahrenheit in the last decade．Since most of Greenland's ice is on land，seas will rise as the ice melts．If all Greenland's ice sheet melted，oceans would be 15-20 feet higher．Nobody expects that to happen anytime soon．
68．Which of the following about the glaciers is TRUE？C
A．Glaciers only lie in Greenland．
B．Water in glaciers is more than sea water．
C．Glaciers sometimes float on the water．
D．Glaciers can increase the water level of lakes．
69．According to the text，we know that GreenlandB．
A．belongs to Canada
B．is the largest island in North America
C．is all covered with glaciers
D．is sinking under the sea level
70．Which of the following may be the result of the disappearing of Greenland glaciers？D
A．the climate of the world will be warmer．
B．the glaciers in other area will be bigger．
C．It will be easy for explorers to visit the island．
D．Some coastal cities may be under the sea．
分析 文章讲述了格林兰岛冰川迅速融化的事情，及科学家对他的分析，如果继续恶化，沿海城市将处于一片汪洋之中．
解答 68：C 推断题．从文章A glacier's front is the point where the water is deep enough that the glacier floats．可知冰川的前部位置，由于水非常的深可以将其漂浮起来，故选C
69：B 细节题．从文章Greenland is the world's largest island，covering area more than three times the size of Texas．可知格林兰岛是世界上最大的岛屿，面积是德克萨斯州的三倍多，它属于丹麦，故选B
70：D 细节推断题．从文章If all Greenland's ice sheet melted，oceans would be 15-20 feet higher．可知如果格林兰岛的冰原全部融化，海平面将会上升15-20英尺，很明显沿海城市将处于一片汪洋之中，故选D
点评 本文结构非常明了，文意也很好理解，学生在答题中一定要认真细致的作答以求全对．对于此类说明文的文章一定要将文章仔细的阅读完并理解，结合题目通过题目的关键词进行定位，分析好句子的意思，即可得出答案．
