[单选题]
The diagram shows the carbon
wc/n8ddek/u0 stored in some of Earth’s carbon reservoirs, an
acc)io:ft7a 64b/q*;v tm lz /whhjk 4qf k19od the estimated annual c
v/ bj4aqtz 9);f k:1i*fw7tqkh h4/om6aclocarbon flux, in GT/yr, between reservoirs.
Which is a net flux between two reservoirs in the carbon cycle?
A. Vegetation/soil releases 1 GT of carbon to the atmosphere each year.
B. Vegetation/soil absorbs 1 GT of carbon from the atmosphere each year.
C. Marine biota gain 11 GT of carbon each year.
D. Marine biota lose 11 GT of carbon each year.
参考答案:
B
本题详细解析:
Explanation:
The diagram shows that soil/vegetation absorbs 123 GT of carbon from the atmosphere per year and releases 122 GT of carbon into the atmosphere per year. So, soil/vegetation absorbs a net of 123 GT - 122 GT = 1 GT of carbon per year.
Soil/vegetation gains 1 GT of carbon each year, rather than releasing 1 GT of carbon to the atmosphere (Choice A). Marine biota gain a net total of 11 GT of carbon from the surface ocean but lose 11 GT of carbon to the intermediate/deep ocean so have a net flux of 0 GT of carbon per year. Therefore, marine biota neither gains 11 GT of carbon per year (Choice C) nor loses 11 GT of carbon per year (Choice D).