試題詳解

40. Global warming is a phenomenon in which global temperate is increasing as a result of increasing greenhouse gas concentrations in the atmosphere. Scientists believe that the Earth can tolerate X-Y degree Celsius temperature increase before it passes the point of no return and moves into a positive feedback loop. "X-Y" should be
(A) 1-2
(B) 3-4
(C) 5-6
(D) 7-8