The massive magnitude（震级） 8.8 earthquake that struck the west coast of Chile moved the entire city of Concepcion at least 10 feet to the west, and moved other parts of South America as far apart as the Falkland Islands and Fortaleza, Brazil.
These measurements, produced from data gathered by researchers from four universities and several agencies, paint a much clearer picture of the power behind this earthquake, believed to be the fifth-most-powerful since instruments have been available to measure earthquake.
Buenos Aires, the capital of Argentina moved about 1 inch to the west. And Chile's capital, Santiago, moved about 11 inches to the west-southwest. The cities of Valparaiso and Mendoza, Argentina, northeast of Concepcion, also moved.
The quake's epicenter (震中) was in a region of South America that's part of the so-called “ring of fire,” an area of major seismic（地震的） stresses which encircles（环绕，包围） the Pacific Ocean. All along this line, the plates on which the continents move press against each other.
Mike Bevis, professor of earth sciences at Ohio State, has led a project since 1993 that has been measuring crustal（地壳的）movement in the Central and Southern Andes. The effort is called the Central and Southern Andes GPS Project, or CAP.
Ben Brooks, an associate researcher with the School of Ocean and Earth Science and Technology at the University of Hawaii, said that the event, offers a unique opportunity to better understand the seismic processes that control earthquakes.
“We now have modern, precise instruments to evaluate this event, and because the site borders a continent, we will be able to get evidences of the changes it caused.” said Brooks.
What is the main idea of the passage?

A．The earthquake in Chile was dangerous. B．Earthquake often happen in Chile C．The earthquake in Chile moved cities. D．The earthquake in Chile had been predicted.

A．Concepcion B．Buenos Aires C．Santiago D．Valparaiso

A．the fire and the earthquake B．the beautiful places around the ocean C．the plate on which South America lies D．the area around the Pacific Ocean

A．It is under the leadership of Mike Bevis. B．It observes earthquakes worldwide. C．It is designed to watch climate changes. D．It mainly studies the Pacific Ocean.