[解析]
(1)B.写作目的题。根据原文第一段But where did this new volcano come from,and what caused its unpredictable eruption?(但是,这座新火山来自哪里?是什么导致了它不可预测的喷发。)可知作者在第一段提到一个农民的故事是为了引入主题。故选B。
(2)C.代词指代题。根据原文第二段At high enough concentrations,compounds like water or sulfur(硫)form high﹣pressure gas bubbles.When these balls of gas reach the surface,they can burst with the force of a gunshot.And when millions of bubbles explode,the energy can send ash into the air.But before they pop or burst,they act like bubbles of CO2 in a shaken soda.(在足够高的浓度下,水或硫等化合物形成高压气泡。当这些气体球到达地面时,它们会在枪声的作用下爆炸。当数以百万计的气泡爆炸时,能量会将灰送入空气中。但在它们爆炸或破裂之前,它们就像摇动苏打水中的二氧化碳气泡。)可知第2段中带下划线的单词"they"指的是化合物的气泡。A.The bubbles of CO2二氧化碳的气泡;B.The ash of the volcano火山灰;C.Gas bubbles of compounds.化合物的气泡;D.The elements of a soda苏打水的成分。故选C。
(3)A.推理判断题。根据原文第三段Landslides can remove massive quantities of rock from atop a magma chamber or room,dropping the pressure and instantly touching off an eruption.This process is known as "unloading" and it's been responsible for numerous eruptions,including the sudden explosion of Mount St.Helens in 1980.(山体滑坡可以从岩浆室或岩浆室顶部移除大量岩石,降低压力,并立即引发喷发。这一过程被称为"卸载",它导致了多次喷发,包括1980年圣海伦斯山的突然爆炸。)可知关于圣海伦斯山的喷发,正确的是山体滑坡应为其喷发负责。故选A。
(4)D.推理判断题。根据原文最后一段Hopefully,these tools will help us better understand these gas breaks and their explosive eruptions.(希望这些工具能帮助我们更好地理解这些气体破裂和它们的爆炸爆发。)可知从最后一段我们能推断出科学家们对火山爆发的进一步研究持肯定态度。故选D。