In 1778 Bank was elected president of the Royal Society position he held for 43 years.

问题补充：

In 1778, Bank was elected president of the Royal Society, position he held for 43 years.

A. the; the

B. 不填; a

C. a; a

D. 不填 ; the

答案：

A. the; the

(答案→)B. 不填; a

C. a; a

D. 不填 ; the

解析：考查冠词，第一空的president意为总统，在表示职位，头衔的名词前面要用零冠词，第二空表示泛指，意为这是一个他拥有了43年的职位，