Was it because his mother was ill ______ he didn’t go to school?
"_____ of them are not here." means "_____ of them are not here."
We must do something to _____ factories _____waste water into the river before it is cleaned.
What way are you thinking of _____ rid of the flies?
Jack is a good friend _____, he often comes to our home for a visit.
You can say "He went there _____, not _____."