The repairs to the car will cost 500 yuan,--------.

more or less表示“或多或少”,即表示大约的概数,可以与前面的字用逗号隔开.这道题选择C.表示“修理这辆车要花或多或少五百元.”
almost、nearly以及表示否定的scarcely、hardly都是副词,可以修饰动词、副词、形容词和名词.
almost和nearly均可以用于肯定句,如：
She fell and almost broke her neck.
He nearly always arrives late.
almost可以与否定字连用,但是nearly不可以,almost与否定字连用的时候,相当于hardly和scarcely,表示“几乎不”.如：
He ate almost nothing.
There is almost no space to sit.
hardly也可以表示“几乎不”,相当于almost加上动词的否定式,如：
So quietly did she sing that I could hardly hear her.
表示一件事紧接另一件事发生的句子中,可以把hardly和scarcely置于句首,这时的句子要用部分倒装的形式,即把助动词和情态动词置于主语之前.如：
Hardly had we arrived when it began to rain.
希望我能帮助你解疑释惑.