The northern lights, known as the aurora borealis, are one of nature’s most dazzling spectacles. Science is still not certain __11__ exactly what these lights are and what causes them. Sometimes, the brilliant rays of light spread upward in the shape of a fan.__12__ , they flash here and there like giant searchlights. Farther north, the aurora frequently looks like fiery draperies which hang fromthe sky and sway __13__ while flames of red, orange, green, and blue play up and down the moving folds. According to scientificmeasurements, this discharge of light __14__ from 50 to 100 miles above the earth. It is seen __15__ around the Hudson Bayregion in Canada, in northern Scotland, and in southern Norway and Sweden.
【題組】11.
(A) due to
(B) instead of
(C) as to
(D) in spite of