百分数作主语时，谓语动词怎么变

分数：分子用基数词,分母用序数词,分子大于1时,分母用复数,分子分母之间可以用使用连字符,也可以不用1/8：one-eighth或者 one eighth分子大于一：2/8：two-eighths 或者 two eighths假分数 5/3 :one and two-thirds 或者 one and two thirds百分数直接在数字后面用percent15%：fifteen percent分数百分数作主语时,关键看后面名词是否可数来决定单复数：Two fifths of the land in that district is covered with tress。这里land不可数,因此谓语用单数Two fifths of the boys in the class have finished the work。这里boy可数,谓语使用复数