25.
(A) against
(B) beneath
(C) between
(D) over

A tsunami is a series of ocean waves that sends surges of water, sometimes
reaching heights of over 30.5 meters, onto land. These walls of water can cause
widespread destruction when (26) crash ashore. The awe-inspiring waves are typically
caused by large, undersea earthquakes. When the ocean floor at a plate boundary rises
or (27) suddenly, it displaces the water above it and launches the rolling (28) that will
become a tsunami. Tsunami may also be caused by underwater landslides or volcanic
eruptions. Thus, most tsunamis, about 80 percent, happen within the Pacific Ocean’s
“Ring of Fire,” a geologically active area (29) volcanic eruptions and earthquakes are
common. The best (30) against any tsunami is early warning that allows people to see
higher ground. The Pacific Tsunami Warning System, a network of 26 nations, is
headquartered in Hawaii. More similar systems are needed in the future to protect
coastal areas worldwide.

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