The sailing ships were superseded by the steamships.是什么意思？

The sailing ships were superseded by the steamships.

帆船已被汽船所取代.

the

art. 指已提到的人（物），指说话人与听者已知的人（物），用于独一无二的事物前，与形容词最高级和序数词连用；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

Sailing

n. 帆船运动，（乘帆船的）航行，（轮船的）航班；v. 驾驶( sail的现在分词)，起航，坐船旅行，掠；adj. 航行的；

例句
He finds the comparison of insect wings with a sailing boat useful up to a point...
他发现把昆虫的翅膀比作一艘帆船在某种程度上是有用的。

ships

n. 船( ship的名词复数 )，<口>宇宙飞船，（舰船上的）全体船员，运气；

例句
An armada of U.S. Navy ships participated in the invasion.
美国海军舰队参加了入侵行动。

were

be的过去时复数和第二人称单数形式，有时代替 was,用于条件从句、动词 wish 之后等；

例句
Shops, houses, and vehicles were set ablaze.
店铺、房子和车辆全都陷于火海。

superseded

adj. [医]被代替的，废弃的；v. 取代，接替( supersede的过去式和过去分词 )；

例句
Hand tools are relics of the past that have now been superseded by the machine.
手工工具是历史的遗物，现在已经被机器所取代。

by

prep. 在…旁边，表示方式，由于，经过；adv. 经过，表示保留或保存时用，短暂拜访；

例句
...expensive make-up that we saw being advertised by a beautiful model...
我们所见的由一位漂亮模特代言的昂贵化妆品

steamships

n. 汽船，大轮船( steamship的名词复数 )；

例句
Berths on steamships can be booked a long while in advance.
轮船上的床位可以提前多日预订.