Олимпиадные задания. 10 класс.

 Insert the right articles in the gaps below. Write “—” when no article is needed.

The Mystery of Lightning

For 1) _______ centuries, 2) _______ lightning has been a source of awe and dread. In 3) _______ ancient times, it was seen as a weapon of 4) _______ gods, such as Zeus in 5) _______ Greece. Today, scientists understand it as 6) _______ electrical discharge between 7) _______ atmosphere and the ground. 8) _______ flash of lightning can heat 9) _______ surrounding air to temperatures five times hotter than the surface of 10) _______ Sun. This rapid heating causes the air to expand violently, creating 11) _______ sound wave we know as 12) _______ thunder.

 Keys:

1) —, 2) —, 3) —, 4) the, 5) —, 6) an, 7) the, 8) A / The, 9) the, 10) the, 11) the, 12) —