4. A。推断题。根据第4段第2句话 Bandwidth(宽带) is the limiting factor for
sending complex(复杂) medical
pictures around the world - CT photos being one of the biggest bandwidth users可知答案为A。
(3)
Scientists
are uncovering the secrets of two port cities lost under the waters of the
Mediterranean Sea, a researcher said yesterday.
Herakleion
and Menouthis were rich and proud cities until something reduced them to rubble
(碎石) and buried them in the mud
beneath 30 feet of sea water, French underwater explorer Franck Goddio said at
the American Geophysical Union conference.
“This
is a mystery that is ongoing,” said Goddio, a founder of the European Institute
of Marine Archeology, a Paris-based underwater research organization backed by
the wealthy Hilti Foundation of Liechtenstein(列支敦士登基金会).
The
destruction of the twin port cities has haunted Goddio ever since he happened
upon the site about 15 miles from Alexandria while exploring sunken ships from
Napoleon’s fleet.
Goddio
and his group of expert divers, marine archeologists(海洋考古学家) and others, are using high powered
vacuums, satellite navigation systems and sophisticated sonar(声纳) to excavate(挖掘) the sunken cities from underneath a
carpet of silt about one meter (three feet) high.
Walls
of shops, remains of streets and gold artifacts have been found and recovered.
Some
experts believe that the port cities were destroyed by a series of massive
earthquakes, much like the quakes scientists believe felled Troy(特洛伊城), Jericho and other ancient cities. The
uniform direction of the collapsed columns and walls suggest an earthquake,
Goddio said, but no fault lines have been found nearby.
Other
researchers believe a massive wave, caused by either an offshore earthquake or
a distant underwater landslide, could explain the catastrophe. Still others
think rising seas and a shift in the Nile River outlet doomed the cities.
“The
argument, as you can see, continues,” Goddio said.