Police hope that a member of the public will be able to ________a man seen acting suspiciously a few hours before the murder took place.

A．as far as energy source is concerned, salt water is useless because of its chemical properties
B．the working principle of an vibrating water column is to use water as a direct power driving a generator
C．Britain is pursuing a method that the Japanese have already put into practice
D．Britain is the most advanced country in developing new energy source

A．two currents of different temperatures run near to each other and not far away from land
B．two currents of different temperatures run near to each other but far away from land
C．the ocean water is heated by the sun
D．the ocean water gets cool