判断题
In 1991 Philippines witnessed the second largest volcanic eruption that hit an area with large population.
【正确答案】
B
【答案解析】[听力原文]1-10 The second-largest volcanic eruption of the 20th century, and by far the largest eruption to affect a densely populated area, occurred at Mount Pinatubo in the Philippines on June 15, 1991. The eruption produced high-speed massive falling of hot ash and gas, giant mudflows, and a cloud of volcanic ash hundreds of miles across. The impacts of the eruption continue to this day. A huge cloud of volcanic ash and gas rose above Mount Pinatubo, Philippines, on June 12, 1991. Three days later, the volcano exploded in the second-largest volcanic eruption on Earth in this century. Timely forecasts of this eruption by scientists from the Philippine Institute of Volcanology and Seismology and the US Geological Survey enabled people living near the volcano to evacuate to safer distances, saving at least 5 000 lives. On July 16, 1990, a magnitude 7.8 earthquake (comparable in size to the great 1906 San Francisco, California, earthquake) struck about 60 miles (100 kilometers) northeast of Mount Pinatubo on the island of Luzon in the Philippines, shaking and squeezing the Earth's crust beneath the volcano. At Mount Pinatubo, this major earthquake caused a landslide, some local earthquakes, and a short-lived increase in steam emissions from a pre-existing geothermal area, but otherwise the volcano seemed to be continuing its 500year-old sleep undisturbed. In March and April 1991, however, molten rock rising toward the surface from more than 20 miles beneath Pinatubo triggered small earthquakes and caused powerful steam explosions that blasted three outlets on the north flank of the volcano. Thousands of small earthquakes occurred beneath Pinatubo through April, May, and early June, and many thousand tons of noxious sulfur dioxide gas were also emitted by the volcano. Following Mount Pinatubo's disastrous eruption on June 15, 1991, thou sands of roofs collapsed under the weight of ash made wet by heavy rains. Ash deposits from the eruption have also been remobilized by monsoon and typhoon rains to form giant mudflows of volcanic materials, which have caused more destruction than the eruption itself. Nearly 20 million tons of sulfur dioxide were injected into the upper atmosphere in Pinatubo's 1991 eruptions, and dispersal of this gas cloud around the world caused global temperatures to drop temporarily (1991 through 1993) by about 1 degree. The eruptions have dramatically changed the face of central Luzon, home to about 3 million people. About 20 000 indigenous Aeta highlanders, who had lived on the slopes of the volcano, were completely displaced, and most still wait in resettlement camps for the day when they can return home. About 200 000 people who evacuated from the lowlands surrounding Pinatubo before and during the eruptions have returned home but face continuing threats from lahars that have already buried numerous towns and villages. Rice paddies and sugar-cane fields that have not been buried by lahars have recovered; those buried by lahars will be out of use for years to come.
独白第一句即指出：The second-largest volcanic eruption... on June 15, 1991，但题句中没有of the 20th century这——限定词，因此the second-largest volcanic eruption所指不对，故题句是错误的。
判断题
The volcanic eruption affected hundreds of miles across in Philippines.
【正确答案】
A
【答案解析】独白第二句指出：The eruption produced... hundreds of miles across，即这次火山爆发影响的范围有数百英里，题句是正确的。
判断题
Minor earthquakes due to the rising molten rocks triggered the volcano in Philippines in 1991.
【正确答案】
B
【答案解析】独白第三段倒数第四句指出：In March and April 1991... triggered small earthquakes and caused... the volcano，即升到地表的熔岩引起了许多小地震，使得火山强大的蒸汽在火山北侧炸出了3个出口。将题句与这一句进行对照可知题句是错误的，因为并不是这些小地震激发了火山的爆发。
判断题
On June 15, 1991, thousands of roofs collapsed due to the wet volcanic ash deposits.
【正确答案】
B
【答案解析】题句中的时间状语on June 15, 1991与独白第三段倒数第二句中的Following Mount Pinatubo's disastrous eruption on June 15, 1991不符，因此题句是错误的。
判断题
Pinatubo's 1991 eruptions deepened the global environment pollution.