It would be impossible to perform a controlled experiment on which of the following objects? a. two types of food
b. zebras in a zoo
c. the solar system
d. a piece of metal

d. Tree roots improve soil water retention.

Deforestation is a process of removing or clearing forests or other vegetation in order to obtain land for agriculture, construction and other purposes. Deforestation results in decrease in vegetation cover from earth, loss of biodiversity, affects water, oxygen and carbon cycles. Plants and trees are efficient in capturing free flowing water from a water source by absorption through roots during disaster like flood but removal of trees by deforestation can make the area prone to high risk of flood as roots will not be available to absorb water.