The jet stream influences global weather by doing what? a: producing thunderstormsb: moving weather from one place to anotherc: producing areas of high pressured: producing floods

I'll assume B. Moving weather from one place to another and/or C. Producing areas of high pressure because those make the most sense and the Jetstream is a high pressured sheer or "gust" so to speak of wind and because its moving through the clouds it is assumed possible that it could move storms but severe storms are certainly caused by higher pressure.

Answerstratovolcanoes///near or in the ring of fire;

Magma forms by partial melting of upper mantle and crust. partial melt means that only a fraction of the available material forms a melt, and that the remainder stays solid. the partial melt rises because of its lower density and ascends through he crust. this is so conclusive mean the answer would be magma igneous rocks or balistic magma.