阿摩線上測驗
39. It is imperative that every precautionary measure _____ to safeguard long-term sustainability.
(A) is taken
(B) be taken
(C) was taken
(D) being taken
答案：登入後查看
統計： A(17), B(39), C(6), D(1), E(0) #3873135
統計： A(17), B(39), C(6), D(1), E(0) #3873135
