The dependent variable is something that you measure or observe to find out whether there was a difference between your control bottle and experimental bottle. (ex: seed height) What will you be measuring and observing?

igneous rocks are formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.  

the composition depends on the source magma. there are almost a thousand types of composition found till now.  

hope this

i would think a oil tanker that has leaked in a bay

i'm thinking 600 feet deep in one of the finger lakes.