NO.PZ2024010503000015
问题如下：
Which of the following statements about CO2 is most accurate?
选项：
A.CO2 levels are the highest they have been in over 800,000 years.
B.About 10% of CO2 emissions from the 17th century onward occurred in the last 30 years.
C.Agriculture and land-use changes account for the highest share of CO2 emissions.
解释：
A is correct. Atmospheric carbon dioxide (CO2) is at levels not seen over the past 800,000 years. More than half the CO2 emissions (as opposed to 10%) from the late 17th century onward have occurred in the last 30 years. It is the burning of fossil fuels rather than agriculture and land use changes that cause the highest share of CO2 emissions.请问B选项怎么理解？不明白选项的意思
