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Earthquakes often happen near volcanoes, but this is not always true. The centers of some are {{U}} (1) {{/U}}. The bottom of the sea suddenly {{U}} (2) {{/U}}. The powerful forces inside the {{U}} (3) {{/U}} break the rocks. The coast is shaken and great waves appear. These waves travel {{U}} (4) {{/U}} and rush over the land when they reach it. They are strong enough to {{U}} (5) {{/U}} houses and other buildings; sometimes they break {{U}} (6) {{/U}} than the earthquake itself.
Very often fires followed the {{U}} (7) {{/U}} earthquakes. In 1906, the great earthquake at San Francisco broke the gas-pipes. The gas {{U}} (8) {{/U}}, and soon large numbers of fires were burning in the city. The water-pipes were also {{U}} (9) {{/U}}; so it was not possible to put the fires out. There was {{U}} (10) {{/U}}. The Tokyo earthquake of {{U}} (11) {{/U}} happened just before the middle of the day. People were {{U}} (12) {{/U}} on t