Circles a and b are externally tangent to each other. from center b a tangent is drawn to circle a intersecting the circle at c. if bc is twice the radius of circle a compute the ratio of the area of circle a to the area of circle b.

Pleas give me brief explanation about deterministic model in advanced hydrology

The biome pictured above is found in areas such as kenya and south africa. the land is grass-covered with very few trees and gazelles and other grazers are common here. why does this biome have a low population of trees? a) large grazing animals destroy the trees. b) it is a deforested rainforest with poor soil. c) it has high temperatures and low precipitation. d) it has a long rainy season followed by flooding.

Which amusement park ride utilizes periodic motion a.slide b.bumper cars c.giant swing d.roller coaster