__Having studied ___________(study) volcanoes for many years,I am still amazed _at __ its beauty as well _as __ its potential to cause great damage.
翻译：研究火山很多年了,但我任然惊诧于它的美丽和它的强破坏力.
for many years,表明要用完成时,have放在句首,要用v-ing.所以第一空填Having studied
be amazed at 这是一个词组,表示 惊诧于 ,就不用给解释了.
as well as 也是一个词组.表示 也 .