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
【用戶】我愛阿,阿愛我
【年級】
【評論內容】it is essential that + S +(should) +V原形