本题目来源于试卷: Interaction & Interdependence C.9 Transfers of Energy & Matter，类别为 IB生物学
[单选题]
Which of the followingpxt3i 0 v7-yzk prolxn: ;r9ylj, icesses in the Carbon cycle requires the longest time?
A. Compounds present in plankton and plants turn into fossil fuels.
B. Respiration breaks down organic compounds into carbon dioxide.
C. Photosynthesis captures solar energy and fixes $CO_2$
D. Forest fires, which occur naturally and burn the underbrush clean the forest floor of debris.
参考答案: A
本题详细解析:
Explanation: Heat and pressure from the Earth’s crust decompose the remains of dead plants and animals over millions of years to form oil, natural gas or coal (fossil fuels). Respiration (Choice B) takes place in a relatively short time as does photosynthesis which requires light to synthesize organic compounds (Choice C). Forest fires (Choice D) often occur naturally and release carbon dioxide into the atmosphere. Global warming has increased the number of wildfires.
| 
