n (astronomy) an indistinct surface feature of Mars once thought to be a system of channels; they are now believed to be an optical illusion
n a bodily passage or tube lined with epithelial cells and conveying a secretion or other substance
n long and narrow strip of water made for boats or for irrigation
v provide (a city) with a canal
n. 运河( canal的名词复数 ); 管道; 气管; 食道