今天我們要學(xué)的詞是 biennial.

Biennial 的意思是兩年一次的。North Korea is no longer South Korea's “enemy,” though Pyongyang's nuclear program still poses a security threat, according to Seoul's biennial defense document published recently. 首爾最近公布的兩年一期的國(guó)防文件中稱，盡管平壤的核計(jì)劃仍構(gòu)成安全威脅，但朝鮮不再是韓國(guó)的“敵人”。

While the biennial election of all 435 members of the House and one-third of the Senate typically lacks the voter interest compare to a presidential election every four years, last year's midterms were an exception. 相比（美國(guó)）四年一次的總統(tǒng)選舉，選民們通常對(duì)眾議院全體435名議員和參議院三分之一議員兩年一次的選舉缺乏興趣，但去年的中期選舉是個(gè)例外。