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

<上一题目录下一题>

热门试题

单项选择题

Which of the following is true about the U.S. Navy underwater listening network

A．It is now partly accessible to civilian scientists.
B．It has been replaced by a more advanced system.
C．It became useless to the military after the cold war.
D．It is indispensable in protecting endangered species.

单项选择题

Why is such simplistic advice (Line 1, Para. 3) impossible to follow

A．No one can stay on the same job for long.
B．No prescription is effective in relieving stress.
C．People have to get married someday.
D．You could be missing opportunities as well.