Black rocks and yellow sandbanks emerge suddenly from time to time in the river, and we have to steer a devious course downstream through very narrow channels marked by buoys.

• 现在是“枯水季节”，江中突然露出一块黑色礁石，一片黄色浅滩，船常常在很狭窄的两面航标之间迂回前进，顺流驶下。