What are the environmental factors that define a tropical rainforest environment?

Is this mrna or rna need need the answer in a hurry

Which of the following is likely not involved in this example of ecological succession? a) the rotting remains of plants add to the fertility of the soil. b)the soil becomes so fertile that eel grass is replaced by other plant species. c) the roots from plants stabilize the sediment, keeping it in place. d) the concentration of salt becomes so high that all plant life is destroyed.

Math focus 4. calculate a map has index contours at 250 m, 500 m, and 750 m. what is the contour interval?