eager to get access to the president the boy in northern America wrote a letter to him.

问题补充：

eager to get access to the president, the boy in northern America wrote a letter to him.

A. Much

B. Too

C. As

D. So

答案：

A. Much

(答案→)B. Too

C. As

D. So

解析：too eager to do sth. “太渴望做某事”，在此处作状语，不能理解为太渴望而不想做某事。类似表心理活动的词语还有glad, pleased, excited, ready, willing等。much作副词一般修饰形容词和副词的比较级。