Astudent wants to test the effect of nitrogen rich fertilizers on the growth of rose bushes. which of the following is a variable that must be kept constant?

growth of the rose bush
amount of water the rose bush receives
the use of nitrogen rich fertilizer

it would be rhyolitic hope this

weathering - colorado river carves land in arizona to form the grand canyon. cracks form in a sandstone wall surrounding a house. a marble statue near the science museum is changing color due to rainfall

erosion - after a rainstorm, soil and rock piees litter the roadways. the sand dunes in the sahara desert are changing shape.

here's your answer.

if you listed your answers right then i believe your answer is b.