阿摩線上測驗
38. Not only the marine biologist but also her research colleagues ________ trying to locate the endangered species for
years.
(A) is
(B) are
(C) has been
(D) have been
答案：登入後查看
統計： A(20), B(83), C(45), D(300), E(0) #2062431
統計： A(20), B(83), C(45), D(300), E(0) #2062431
