老师好，我做了一篇雅思阅读，有几句话的语法现在想不清楚，请老师解答。谢谢！

1. The gases trapped inside the boiling rock expand suddenly, the lava glows with heat, it begins to froth, and it explodes with tremendous force.

请问老师inside后面怎么能用expand呢？

2. Then the slightly cooler lava following it begins to flow over the lip of the crater. 

请问老师 Then the slightly cooler lava following 这段话是什么语法现象，尤其following.

3. A Volcanoes are the ultimate earth-moving machinery. A violent eruption can blow the top few kilometres off a mountain, scatter fine ash practically all over the globe and hurt rock fragments into the stratosphere to darken the skies a continent away.

请问老师  darken the skies a continent away 中 a continent away是什么语法现象？ 

4. Volcanism, the name given to volcanic processes, really has shaped the world.

请问老师 the name given to volcanic processes 在这句话中是同位语作用么？ given to volcanic processes 是做定语修饰 the name 么？

5. The quantity of these gases, again multiplied over 3,500 million years, is enough to explain the mass of the world’s atmosphere.

请问老师  again multiplied over 3,500 million years 在这里边是定语修饰 these gases 还是和is enough to 属于相同的成分？

 请老师帮助我，谢谢。学生一直在线。