How pleased the detective was _____what his customer told him!

She looks forward every spring to _____the flower-lined garden．

_____to his research work, the professor cared little about any other things．

The Olympic Games,     in 776BC, did not include women players until 1912.
A. first played  B to be first played  C first playing   D to be first playing

---What did the old man say?
---Oh, he told us _________ football in the busy street.

When I entered the classroom, I saw the students _____ in their seats.