Question

a small secondary opening of a volcano​

Answer 1

Answer:

the opening of volcano is called volcanic vent

A volcanic vent is an opening exposed on the earth's surface where volcanic material is emitted. All volcanoes contain a central vent underlying the summit crater of the volcano.

Answer 2

Answer:

Stratovolcanoes

Explanation:

Stratovolcanoes result from a conduit system of vents leading from a magma reservoir beneath the surface. When dormant, they typically have steep concave sides that sweep together at the top around a relatively small crater.