1.When the one chair in the room was at its usual place before the table, the canal was unnavigable.
若是屋里唯一的椅子放在了桌前平常的地点，“运河”航行就会受阻。
2.It is about 435 mi (700 km) long and largely unnavigable.
该河长约700公里，且大部分河段不通航。
