On average these footprints are 14 to 18 inches long 5 to 9 inches wide and much larger

问题补充：

On average, these footprints are 14 to 18 inches long, 5 to 9 inches wide and much larger than of a human.

A. that

B. it

(答案)C. those

D. one

答案：

@@A. that@@B. it@@(答案)C. those@@D. one

解析：本题句意“这些足迹评价是14到18英寸长，5到9英寸宽，比一个人的脚印大得多”。前面提到的footprints是复数，与人的脚印比，也是复数。故用those。