11. The accident is thought _____ by rocks on the railway line.
(A) to have caused
(B) to have been caused
(C) have been causing
(D) that has been causing

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統計： A(7), B(33), C(2), D(4), E(0) #1590150

詳解 (共 1 筆)

#3307371

關鍵字在by

本句即為被動語態

故被動語態中必須要有be +pp的元素

A)缺beV

C)缺pp

D)缺pp

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