染雾初中英语语法之分数表达
分数表达：
二分之一: half a / an 或a half. 如：
half an hour = a half hour半小时 It’s half past seven.(省略冠词)
以下情况中，分子(基数词)若超过一，分母(序数词)需加s：
三分之一: a / one third 三分之二:
四分之一: a / one fourth 或a / one quarter
四分之三: three fourths或three quarters.
五分之一: a / one fifth 五分之二: two fifths 其它类推。
若分数所在of短语作主语，谓语依of后的名词而定：
A third of the boys have passed the test. A third of the work has been over.
Two fifths of the students are on time. Two fifths of the 初二 land is polluted.
(of后是可数名词复数时，谓语用复数；of后是不可数名词时，谓语用单数。)
