問題詳情
19. They haven’t _____ an AIDS vaccine.
(A) yet developed
(B) developed already
(C) developing
(D) developing yet
(E) already developing
參考答案
答案：A
難度：困難0.392857
統計：A(11),B(6),C(1),D(1),E(2)
用户評論
【麻糬】評論
They haven’t _____ an AIDS vaccine. have + p.p 現在完成式 →從過去 繼續到現在 都還沒開發愛滋疫苗(A) yet developed yet 尚未(B) developed already already 已經(C) developing (D) developing yet (E) already developing