A-A+
How much were the CO2 levels before the Indust
问题详情
How much were the CO2 levels before the Industrial Revolution？
A．400 parts per million.
B．280 parts per million.
C．120 parts per million.
D．680 parts per million.请帮忙给出正确答案和分析，谢谢！
参考答案
正确答案：B
本题设题点在数字信息处。根据句(10)可知，工业革命之前的二氧化碳水平是280ppm，故答案为[B]。
