Obsidian is a rock with glass-like characteristics. obsidian is formed by rapid what and why? (a) weathering(b) erosion(c) cementation(d) cooling

Plsss > .< compare and contrast the characteristics of flatworms rounds worms and earthworms

This is a situation in which genes are attached to an organism's sex chromosomes; the sex of an organism influences the expression of a gene.

Ascientist is designing an investigation to study the impact of invasive bird populations on local, native bird populations at backyard bird feeders. what population is most likely to be a control group for the investigation? amount of food number of bird feeders invasive bird populations local backyard birdfeeders without food