[问答题]
The following graphs show
- gp; hthhw4b*the concent
5,h8.+ lh3ysqi+bt x ae.svvxration of atmospheric carbon dioxide over time
+yxl sxq5ats, he i.vv3+bh8. at Mauna Loa Observatory in Hawaii, United States.
1.Describe the overall trend in atmospheric carbon dioxide levels over time.
2.State one factor that has significantly contributed to increases in atmospheric carbon dioxide concentration as seen in the graphs.
3.Explain why the concentration of atmospheric carbon dioxide fluctuates annually.