阿摩線上測驗
12. Many species have been depleted, and there are things need to be done in different areas __ the sustainability of reefs.
(A) to ensure
(C) ensure
(B) which to be sure
(D) ensured
答案：登入後查看
統計： A(0), B(0), C(1), D(0), E(0) #3370812
統計： A(0), B(0), C(1), D(0), E(0) #3370812
