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

It can be inferred from the passage that ______.

A．new radio devices should be developed for tracking the endangered blue whales
B．blue whales are no longer endangered with the use of the new listening system
C．opinions differ as to whether civilian scientists should be allowed to use military technology
D．military technology has great potential in civilian use

单项选择题

Daniel and Skip, who saved the lives of the two children, ______.

A．had been good friends
B．were two close friends of Joy Warren's
C．were Joy Warron's neighbors
D．were strangers before the accident