A、Southern Canada. B、Central Russia. C、North America. D、Eastern Mongolia. B

A total solar eclipse occurred this year. A solar eclipse occurs when the Moon passes between the Earth and the Sun, thereby totally or partially obscuring the Earth’s view of the Sun. A total solar eclipse occurs when the Moon’s apparent diametre(直径) is larger than the Sun, blocking all direct sunlight and turning day into darkness. And it occurs in a narrow path across the surface of the Earth, while a partial solar eclipse will be visible over a region thousands of miles wide. It had a magnitude of 1.0394 that was visible from a narrow corridor through northern Canada, Greenland, central Russia, eastern Kazakhstan and western Mongolia. Occurring north of the Arctic Circle, it belonged to the so-called midnight sun eclipses. The largest city on the path of the eclipse was Novosibirsk in Russia. The total eclipse lasted for two minutes, and covered 0. 4% of the Earth’s surface in a 10 200 km long path. It is the 47th eclipse of the 126th Saros cycle, which began with a partial eclipse on March 10, 1179 and will conclude with a partial eclipse on May 3, 2459. It was described by observers as special for its colors around the horizon. There were wonderful oranges and reds all around, the clouds lit up, some dark in silhouette (侧影) , some golden, glowing yellowy-orange in the distance. You could see the shadow approaching against the clouds and then rushing away as it left."
19.  When does solar eclipse happen?
20.  Where can the eclipse be seen?
21.  How long did this total eclipse last?