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1. |
What is the concentration of carbon dioxide in the atmosphere? |
A. | 3.5 x 10<sup>6</sup> ppm |
B. | 1.0 x 10<sup>2</sup> ppm |
C. | 1.6 x 10<sup>5</sup> ppm |
D. | 1.0 x 10<sup>3</sup> ppm |
Answer» B. 1.0 x 10<sup>2</sup> ppm | |