Question

【题目】Things should ________ here before you enter the library.

A. keeps B. are kept C. be kept D. keep

Answer 1

【答案】C

【解析】句意“在你进图书馆前，东西要保留在这里”。thing与keep之间为被动，且空前有情态动词，要用动词原形be。故选C。