Was it in the factory_____ you worked five years ago___ you learned the technique?
He let me repeat his instructions __________ sure that I understood what was __________ after he went away.
David couldn't tell __________ from far away whether the green traffic light meant going straight or turning left.
-Are you a volunteer now?-No, but I __________. I worked for the City Sports Meeting last year.
He used to __________cards, but now he is used to __________ a walk after supper.
Whenever my parents talk with me, they always __________ great importance to how important and necessary it is for us young people __________ ourselves both in work and in life.