Question 16 is based on the passage you have just heard.

听力原文

    Mount Etna is one of the most active volcanoes on Earth. The mountain has been in a state of near continuous eruption for half a million years. Exploring the Etna geographical area reveals a history written in fire. Before the eruptions, it was covered by forests of pine trees. Located in southern Italy, Etna is the highest active volcano in Europe. (16) However, its height often changes when volcanic material accumulates during eruptions and subsequently collapses.

    Few volcanoes in the world have an eruption history so thoroughly documented by historical records. Etna’s eruption history dates back as far as 1500 BC. Some 200 eruptions have been recorded down through the centuries, but compared with other volcanoes, most of its eruptions have so far been fairly light in terms of death and destruction. Only about 100 deaths have been attributed to the volcano. The mountain hasn’t been entirely harmless, however. In 1928, it destroyed the town of Mascali.

    (17) Over the centuries, Etna’s lowest slopes have been shaped by human hands to take advantage of rich soils for growing grapes, apples and nuts. Local people have also carved out over 200 caves in the soft rock, and used them for everything from sacred burial places to food storage. Large mammals once wandered the volcano’s slopes, but today, foxes, wild cats, rabbits and mice are more common. (18) Some of those small mammals help to sustain such big birds as golden eagles.

16. What does the speakers say about Mount Etna?

 解析：C。根据录音可知，埃特纳火山爆发时形成的火山物质堆积和之后的坍塌都使埃特纳火山的高度发生变化，C项与文意相符。录音中说到埃特纳火山爆发的历史可以追溯到公元前1500年，并不是说它有1500年记载的历史，故排除D项。A、B项在文中没有提及，故排除。