第33题: [单项选择]The Public Transport Commission’s commitment to running our city’s trains and buses as ______ as possible has reduced cost to the taxpayer by 5%. A. efficient B. efficiency C. efficiently D. efficiencies 参考答案:C 答案解析:横线处需要填入形容词或副词。填入形容词可修饰前面的名词或充当表语,填入副词则修饰动词。根据本句结构,横线处所填单词需要修饰running。故选副词(C)efficiently。