問題詳情
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
參考答案
答案：B
難度：適中0.409639
統計：A(26),B(34),C(4),D(16),E(0)
用户評論
【我愛阿，阿愛我】評論
it is essential that + S +(should) +V原形