Question

【题目】WWF ________ one of the most important charities since 1961.

A. was B. has been C. had been D. would be

Answer 1

【答案】B

【解析】

句意：世界自然基金会自1961年以来一直是最重要的慈善机构之一。A. was一般过去时；B. has been现在完成时；C. had been过去完成时；D. would be过去将来时。since 1961自1961年以来，表示到目前为止的时间段，用于现在完成时态的句子中，故答案为B。