How long have you read this book?.A. In 1980 B. Three years agoC. Since three years D. Si

问题补充：

How long have you read this book?

.

A. In 1980

B. Three years ago

C. Since three years

D. Since 1980

答案：

A. In 1980

B. Three years ago

C. Since three years

(答案→)D. Since 1980

解析：In 1980在1980年；Three years ago三年前；Since three years 表达错误，since后面一般接时间点； Since 1980自从1980年以来。根据上文，你读这本书多久了？现在完成时态。选项AB一般用于一般过去时态中，故选D。