阿摩線上測驗
21. _____ by the professor, the students revised their essays carefully.
(A) Having warned
(B) Been warning
(C) Warned
(D) Warning
答案：登入後查看
統計： A(33), B(22), C(96), D(19), E(0) #3426230
統計： A(33), B(22), C(96), D(19), E(0) #3426230
