I spent three hours this book.A. finish readingB. to finish readingC. finishing reading

问题补充：

I spent three hours this book.

A. finish reading

B. to finish reading

C. finishing reading

答案：

解析：根据spend…doing表示“花费时间做某事”，是固定用法；而finish doing表示“做完某事”也是固定用法。所以本题选C。