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. long and narrow strip of water made for boats or for irrigation
v. provide (a city) with a canal
n. 运河, 水道, 管, 沟渠
vt. 开运河
1. The boat sailed smoothly along the canal.
小船在运河上平稳地航行。
2. Many cities have beautiful canals that attract tourists.
许多城市拥有美丽的运河，吸引游客。
3. We can rent a kayak to explore the canal.
我们可以租一只皮划艇来探索运河。