The professor has received the letter to give a lecture in ftinceton Institute.
A. being invited
B. to be invited
C. inviting him
D. invited
网友回答
A. being invited
B. to be invited
(答案→)C. inviting him
D. invited
解析：该题考查分词短语的用法。the letter与invite之间存在主谓关系，故要用现在分词作后置定语。