The eighteenth century developed a completely new kind of novel.
18世纪发展了一种全新的小说。
We got engaged on my eighteenth birthday
在我18岁生日那天我们订婚了。
The siege is now in its eighteenth day.
围困今天已经进入第18天了。
Such disputes multiplied in the eighteenth and nineteenth centuries
这类纠纷在18和19世纪大量增多。
The problem was not solved completely until the invention of the marine chronometer in the eighteenth century.
这个问题之道十八世纪发明了航海经线仪才得以解决。