The following passage has five numbered blanks. For each blank, four alternatives are given. Identify the correct option for each blank :

At 7.17 a.m. on June 30, 1908, an explosion erupted in the forest of Siberia, Russia. The massive explosion ______1______ shockwaves on barometers as far away as England. A ______2______ number of trees-eighty million to be precise- were flattened and lay in a radial pattern. The trees that remained standing ______3______ telegraph poles as they had been stripped of their limbs and bark.

This explosion is ______4______ as the "Tungusta event", and it is generally accepted that this was the result of a cosmic body, such as a meteorite, ______5______ with the earth.