Volcanoes form when reaches the Earth's surface, causing eruptions of and ash. They occur at and constructive plate boundaries (but not at conservative boundaries) and can be of main types - cone, shield and composite - which have different profiles and types of eruption

Volcanoes form when ___molten lava___ reaches the Earth's surface, causing eruptions of __smoke__ and ash. They occur at constrructive and constructive plate boundaries (but not at conservative boundaries) and can be of __3___ main types - cone, shield and composite - which have different profiles and types of eruption

Explanation:

the correct answers are:

a - pacific plate;

it is the biggest oceanic tectonic plate. surrounded on all sides by continental tectonic plates, it is submerging and gradually becoming smaller and smaller.

b - north american plate;

huge continental plate, occupying big portion of the northern hemisphere.

c -eurasian plate;

alongside the north american plate, it is one of the two dominant continental plates in the northern hemisphere.

d - indian plate;

a small continental plate, that has been part of gondwanaland initially, but after the break up of it, moved towards northeast and pushed into the eurasian plate that was once part of laurasia.