二十一世紀(jì)。

21th :／?twenti f?:st／，是twenty-first 的縮寫，第二十一。在序數(shù)詞前，有定冠詞the。century ／'sent?uri／名詞 。世紀(jì);一百年 。Economists has predicted that economic development will still grown up rapidly in the first ten years of the 21th century.經(jīng)濟(jì)學(xué)家預(yù)言在21世紀(jì)第一個(gè)十年里中國(guó)經(jīng)濟(jì)還將快速增長(zhǎng)。Life in the 22nd century will be different from life in the 21th century，because many changes will take place in the new century.22世紀(jì)的生活會(huì)比21世紀(jì)的生活有許多不同，因?yàn)樵谛率兰o(jì)里有許多新變化。Internet is the general information technology in the 21st century.互聯(lián)網(wǎng)，是21世紀(jì)普遍的信息技術(shù)。