21.The copy machine has not been repaired because the part it requires _____

問題詳情

21.The copy machine has not been repaired because the part it requires ______ out of stocks.
(A) is
(B) are
(C) to be
(D) to have been

答案：A
難度：適中0.590909
統計：A(13),B(1),C(5),D(3),E(0)