試題詳解

12. The primary reason that polar regions are cooler than the equator is that ________.
(A) the polar atmosphere is thinner and contains less greenhouse gases than the rest of the atmosphere
(B) the poles are always pointing away from the sun
(C) solar radiation strikes the poles at a lower angle and travels through more atmosphere
(D) the poles are farther from the sun than is the equator
(E) all of the above