his review focuses on three aspects of the nitrogen cycle in streams and rivers. We firstly introduce the distributions and concentrations of nitrogen compounds in streams and rivers as well as the techniques for tracing the sources of nitrogen pollution

it is either c or d and i know for sure it is not a or b

label a cell membrane

label b cytoplasm

label c ribosomes

label d dna

the membrane forms the outside of the cell

cytoplasm is the liquid within

ribosomes are the components within that distribute rna

the dna is the genetic make-up

answer:

convection currents in the magma drive plate tectonics. heat generated from the radioactive decay of elements deep in the interior of the earth creates magma (molten rock) in the aesthenosphere. the aesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the earth that extends to 2900 km.