问题
选择题
You can only borrow two books ____________ if you don’t have a library card.
A. on time B. in time
. from time to time D. at a time
答案
答案：D
题目分析：句意：如果你没有图书卡你一次仅仅只能借阅两本书。A. on time按时B. in time 及时C. from time to time一次又一次D. at a time一次。根据句意，故选D。