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
(B) which to be sure
(C)ensure
(D)ensured
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統計： A(2), B(1), C(1), D(0), E(0) #3354224
統計： A(2), B(1), C(1), D(0), E(0) #3354224
