A swift current occurring in a narrow passage connecting two large bodies of water which is produced by the continuously changing difference in height of tide at the two ends of the passage is called a __________.

A swift current occurring in a narrow passage connecting two large bodies of water   which is produced by the continuously changing difference in height of tide at the two ends of the passage   is called a __________. 


A. rotary current 
B. harmonic current 
C. rectilinear current 
D. hydraulic current



Answer: 



D. hydraulic current