有一题为难倒我了。看上去不难,但是真的不理解,是我考试的第2题。说一个city park 有一个特别的rectangular garden. 它的 length is 50 feet, width is 40 feet. 一个老太太扫公园, she cleaned 5 feet-strip on each side . What percentage of the garden did she cleaned? answer choices : a. 21.75 b.25 c. 35 d.45 e. 66.3333。