In 1778 Banks was elected president of the Royal Society position he held for 42 years.

问题补充：

In 1778, Banks was elected president of the Royal Society, position he held for 42 years.

A. /, a

B. / , the

C. the, a

D. the, the

答案：

(答案→)A. /, a

B. / , the

C. the, a

D. the, the

解析：句意：在1778年, Banks被选为英国皇家学会的会长，这个职位一干就是42年。表职位名词前不用冠词，a position和前面的president是同位语。故选A。

考点: 考查冠词的用法。