It was _____ he came back from Africa that year _____ he met the girl he’d like to marry.
His mother happened _______ when his program was shown on Channel Young.
By the time he was ten, Edison _________ experiments in chemistry.
The businessperson wanted to sell his goods fast; ______, he chose his partner with great care.
Do you know the man____ is talking with Tom?
A dictionary is a book ______ gives the meanings of words.