Costshave

問題詳情：

Costs have ________ 20% over the past years.

A．reduced by                        B．been reduced by

C．reducing to                       D．been reduced to

【回答】

B　reduce為及物動詞，costs應為被減少，所以要用被動語態，排除A、C兩項。另外“減少了”或“增加了”後面的百分數前要用介詞by，to用在“減少到”或“增加到”後面的具體數字前。故B項正確。

知識點：動詞

題型：選擇題