题目

阅读理解 Most maps show places you can visit and howto get there. Most maps, however, were not made by astronomers. At a recentmeeting in Texas, three teams of these scientists presented new maps to showwhere dark matter was. Dark matter neither produces nor reflectslight, which means it's invisible (看不见) to human eyes and to mostscientific instruments. That makes it a challenge to measure and study. Whatmakes the matter more upset: Scientific measurements show that the universeholds about five times as much dark matter as ordinary matter. Making up theknown part of the universe, ord一个角有(　　)条边。A. 一 B. 两 C. 三