Nature has ways of keeping the nitrogen carbon and phosphorus cycles in balance however run off from animal operations and fertilizer in our waterways can result in . a. cultural eutrophication
b. erosion
c. cleaner drinking water
d. an increase in water temperatures

google my dude. if it doesn't show up ask me.

a tetrad is the foursome during meiosis made by two homologous chromosomes that have each already replicated into a pair of sister chromatids.

if you add everything up correctly you should get 69 i got this because 50 plus 19 is it