HELP ME PLZ

What are four key elements of the study of economics?

Aresearcher has developed two stains for use with seed plants. one stains sporophyte tissue blue; the other stains gametophyte tissue red. if the researcher exposes pollen grains to both stains, and then rinses away the excess stain, what should occur? a) the pollen grains will be pure red.b) the pollen grains will be pure blue.c) the pollen grains will have red interiors and blue exteriors.d) the pollen grains will have blue interiors and red exteriors.

In which state was more than 100 billion tons of coal mined in 2005?