A recent study shows that reading in print is better for underst

A recent study shows that reading in print is better for understanding than to read on a Kindle or other electronic devices.
【正确答案】：A recent study shows that reading in print is better for understanding than  reading on a Kindle or other electronic devices.
【题目解析】：比较级的比较主体形式上应该一致，前面是动名词reading in print，则后面也应是动名词reading on a Kindle。