Most of us are used to seasons. Each year, spring follows winter, which follows autumn, which follows summer, which follows spring. And winter is colder than summer. But the earth goes through temperature cycles over much longer periods than those that we experience. Between 65,000 and 35,000 years ago, the planet was much colder than it is now. During that time the temperature also changed a lot, with periods of warming and cooling. Ice melted during the warm periods, which made sea levels rise. Water froze again during the cold periods.
(77) A new study from Switzerland sheds light on where ice sheets melted during the iceage. It now seems that the ice melted at both ends of the earth, rather than just in either northern or southern regions.
This surprised the researchers from the University of Bern. (78) Scientists have long assumed that most of the ice that melted was in the Northern hemisphere (半球) during the 30,000-year long ice age. That belie
A. most of the ice melted in the Northern hemisphere
B. most of the ice melted in the Southern hemisphere
C. The North Pole is colder than the South Pole
D. The South Pole is colder than the North Pole
Most of us are used to seasons. Each year, spring follows winter, which follows autumn, which follows summer, which follows spring. And winter is colder than summer. But the earth goes through temperature cycles over much longer periods than those that we experience. Between 65,000 and 35,000 years ago, the planet was much colder than it is now. During that time the temperature also changed a lot, with periods of warming and cooling. Ice melted during the warm periods, which made sea levels rise. Water froze again during the cold periods.
(77) A new study from Switzerland sheds light on where ice sheets melted during the iceage. It now seems that the ice melted at both ends of the earth, rather than just in either northern or southern regions.
This surprised the researchers from the University of Bern. (78) Scientists have long assumed that most of the ice that melted was in the Northern hemisphere (半球) during the 30,000-year long ice age. That belie
A. the ice can easily just slip into the ocean
B. volcanoes caused the ice to melt
C. melting just in the Northern hemisphere would have been impossible
D. researchers often use the computer models help their research work
Each year more travelers are finding their way to the sun coasts of Mexico; where ancient civilizations once honored the sun, modern sun worshippers are discovering superb vacation destinations. Airlines now schedule weekly flights from major national and international points to a variety of sun coast resort areas.
The peninsula of Baja California provides one of the most splendid vacation sites in the Western Hemisphere. The peninsula is divided into two states: Baja California Norte and Baja California Sur, which are now connected by the Benito Ju rez Trans-peninsular Highway, so that the entire peninsula can be easily reached by car, as well as by sea and air. A chain of new hotels offer deluxe accommodations, but there are also numerous camping grounds, trailer parks and wayside inns for those who prefer casual-living vacations. At the southern end of the peninsula, La Pazi San Jos
A. worshipped the sun
B. built a pyramid to worship gods
C. built roads leading to other places
D. went fishing in waters along the coasts
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