6. Some necessary equipment as well as food and clothes_______ sent to the disaster-hit area since the powerful earthquake occurred.
A. has been B. have been C. is being D. are being
【答案】A
【解析】考查主谓一致。这里的主语是Some necessary equipment，所以谓语动词用单数形式。时间状语为since+过去时，所以用完成时。
