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单项选择题

The highly efficient modem communication system began ______.

A．over a century ago
B．in the middle 1960s
C．in the late 1980s
D．in the year 1980

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单项选择题Which of the following best expresses the main idea of the passage

A．It is optical fibers and lasers that have made the information superhighway possible.
B．People can communicate with each other more quickly now on the Internet.
C．It has taken quite a long time for the Intern to come into existence.
D．If one is seriously ill, he can always get help via the modem communication system.

单项选择题The information superhighway came into existence because of ______.

A．copper wire cables
B．satellite communication
C．optical fibers
D．laser and optical fibers

单项选择题What is the energy source of this so-called solar-sail vehicle

A．Sunlight.
B．Nuclear.
C．Wind.
D．Electricity.

单项选择题What can be inferred from the passage

A．Most scientists are confident that the spacecraft will work well.
B．A more ambitious orbital flight will follow this mission.
C．The author is quite sure that this mission will make impossible technologies seem possible.
D．The key of the engineering of Cosmos I is building wings that can open and pivot.

单项选择题What of the following correctly describe Cosmos I

A．It is a 3-ft. metal pod.
B．It has eight 35-ft. metallic wings.
C．It can fly an altitude above 260 miles.
D．When it flies back to Earth, it will fall into pieces.