1. A volcano is an opening or rupture in a planet’s surface.

P. Erupting volcanoes can pose many hazards.

Q. This opening allows magma, ash and gases to escape from below the surface.

R. Volcanic ash can be a threat to aircraft.

S. Volcanoes are generally found where tectonic plates are diverging or converging.

6. Historically, so-called volcanic winters have caused catastrophic famines.