121. The hard work of the frontline workers _____ crucial in ensuring that the production targets are met and the quality of the products is maintained.
(A)have
(B)have been
(C)has
(D)has been

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統計： A(24), B(44), C(13), D(113), E(0) #3084690

詳解 (共 2 筆)

#6131200
The hard work of the...
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14
0
#7258413

直接看of前面主詞是單數還是複數

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