题目

In our city, one third of the area________covered with green trees, but only forty percent of them ________ well looked after.A.is; have B.is; are C.has; are 答案：【答案】B【解析】句意：在我们城市，三分之一的面积被绿树所覆盖，但只有40%的树木得到了很好地照顾。考查主谓一致。is是，单数系动词；are是，复数系动词；have有，动词原形；has有，三单形式。one third表示“三分之一”，forty percent表示“百分之四十”，当分数和百分数作主语时，谓语动词要与of已知的最小值是    ．