---It has been decades since we last met.---But I still remember the graduation party, believe it or not, ________we toasted for our separation and reunion.
Isn't it time you got down to __________ the papers?
In some parts of London, missing a bus means __________ for another hour.
You can't imagine what great trouble they have __________ the problem __________.
The boy was criticized for forgetting __________ his textbooks to school.
Practice __________ English every day, and you will surely improve your spoken English.