17. To cut down on the garbage, it is essential that all household trash _____ and put into trash bags.
(A) must be classified
(B) be classified
(C) is classified
(D) should classify

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統計： A(49), B(80), C(7), D(25), E(0) #341809

詳解 (共 1 筆)

#331258
it is essential that + S +(should) +V原形
7
0