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。职位、头衔、三餐、学科等前面不使用冠词，president“总统，校长，会长，董事长”，是一个职位，前面不能使用冠词，排除A、C；泛指一个职位，应该使用不定冠词a/an，排除D。故选B。