試題詳解

40. Which of the following statements is correct about biogeochemical cycling?
(A) The phosphorus cycle is a sedimentary cycle that involves the weathering of rocks.
(B) The carbon cycle has maintained a constant atmospheric concentration of CO2 for the past million years.
(C) The carbon cycle is a localized cycle that primarily reflects the burning of fossil fuels.
(D) The phosphorus cycle involves the rapid recycling of atmospheric phosphorus.
(E) The nitrogen cycle involves movement of nitrogen very little of which is chemically altered by either the biotic or abiotic components of the ecosystem.