单项选择题

The passage is chiefly about ______.

A．an effort to protect an endangered marine species
B．the civilian use of a military detection system
C．the exposure of a U.S. Navy top-secret weapon
D．a new way to look into the behavior of blue whales

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热门试题

单项选择题

The underwater listening system was originally designed

A．to trace and locate enemy vessels
B．to monitor deep-sea volcanic eruptions
C．to study the movement of ocean currents
D．to replace the global radio communications network

单项选择题

According to the passage people who have experienced ups and downs may become ______.

A．nervous when faced with difficulties
B．physically and mentally strained
C．more capable of coping with adversity
D．indifferent toward what happens to them