一般不加
如果作定語,要加,而且third后面的s去掉( ) 20. _______ of the earth _______ made up of oceans.A. Two-third; isB. Two-thirds; is C. Two-third; are D. Two-thirds; are選擇什么這里只能選B為什么？你不是說加—，需要去掉后面的s嗎？上面我有講錯(cuò)的地方。請(qǐng)看下面的解釋：two third和two-thirds區(qū)別two third和two-thirds區(qū)別two third是表時(shí)間:兩點(diǎn)三分.two-thirds,表示分?jǐn)?shù):三分之二.順便給你講一下英語中分?jǐn)?shù)的表達(dá)方法:分子用基數(shù)詞,分母用序數(shù)詞,當(dāng)分子大于1時(shí),分母加S,分子與分母之間可以用連字符"-",也可以不用.如三分之一就是one-third或a-third或one third或a third,而五分之二就是two-fifths或two fifths.