Who can reach the book on the top shelf?---Jack can. He is boy of us all.A. taller B.

问题补充：

--- Who can reach the book on the top shelf?

---Jack can. He is boy of us all.

A. taller

B. a tall

C. the tallest

D. much tallest

答案：

A. taller

B. a tall

(答案→)C. the tallest

D. much tallest

解析：句意:谁能摸到书架顶端的书?——杰克能。他是我们当中最高的男生。结合语境可知本句表示在多个中进行对比，用形容词的最高级，最高级前不能用much进行修饰，故选C。