The eighteenth century developed a completely new kind of novel.

　　18世紀(jì)發(fā)展了一種全新的小說(shuō)。

　　We got engaged on my eighteenth birthday

　　在我18歲生日那天我們訂婚了。

　　The siege is now in its eighteenth day.

　　圍困今天已經(jīng)進(jìn)入第18天了。

　　Such disputes multiplied in the eighteenth and nineteenth centuries

　　這類糾紛在18和19世紀(jì)大量增多。

　　The problem was not solved completely until the invention of the marine chronometer in the eighteenth century.

　　這個(gè)問(wèn)題之道十八世紀(jì)發(fā)明了航海經(jīng)線儀才得以解決。