Before you pay a visit to a place of interest, look in your local library _a book about it. A. on B.

Before you pay a visit to a place of interest, look in your local library _a book about it. A. on B. at C. for D. to

正确答案是 C. for。

句意理解：
“在你去游览一个名胜之前，先在你当地的图书馆找一本关于它的书。”
这里的 look for 是“寻找”的意思，表示为了获得某物而查找或搜索。

选项分析：

A. on – “look on” 通常指“旁观”，不符合句意。

B. at – “look at” 是“看……”，表示注视，不强调“寻找”的动作。

C. for – “look for” 意为“寻找”，符合上下文逻辑。

D. to – “look to” 一般指“指望；照顾；注意”，不适用于此处。

完整句子：
Before you pay a visit to a place of interest, look in your local library for a book about it.