The process by which the ocean floor sinks through a deep ocean trench and back into the mantle is known as A.
convection

B.
continental drift

C.
subduction

D.
conduction

the major pests we deal with are insects, weeds and fungal diseases. a pesticide is a product, whether organic or chemical, used to kill the target pest. there are other techniques gardeners should use that can prevent the severe infestations that make the use of pesticides necessary