試題詳解

49. The passage does NOT discuss ________.
(A) the electromotive force generated by the interaction between the solar wind and the Earth’s magnetic field
(B) the enhancement of the auroral discharge by gusts of solar wind generated by a solar flare
(C) that auroras result from large-scale electrical discharge processes surrounding the Earth
(D) that the auroral umbra comes from excited, or ionized atoms and molecules