问题补充：
In our city, citizens have free to the library, which makes it easy for them to read any book they like.
A. time
B. entrance
C. charge
D. access
答案：
A. time
B. entrance
C. charge
(答案→)D. access
解析：考查固定句型，free access to意思“……自由入口”，句子意思“在我们城市，居民可以自由出入图书馆，这使他们读到自己喜欢的书很容易”，free time意思“空闲时间”，free entrance意思“免费入场”，free charge意思“免费”，所以选D
