Describe the four main shapes of galaxies. • Spiral: • Elliptical: • Lens: • Irregular:

What were the main components of earth’s earliest atmosphere? oxygen and ammonia hydrogen and helium oxygen and nitrogen hydrogen and nitrogen

The graph shows the amount of global warming happening in different ecosystems. which populations of organisms will likely decline the most as a result of climate change, and why? a. coral reefs because of the loss of the symbiotic algae living within their bodies b. penguin populations because the fish they eat will move into warmer waters c. mountain-dwelling birds because rising sea levels will relocate their food sources d. large cats in the rainforest because of decreased habitat loss for their prey

Why did the federal government end its support of yucca mountain as a site for long-term storage of nuclear water