--- I didn’t believe you made such a mistake. ---Oh, I’m sorry. I did it ___________. I’m serious.
.A reward of 1,000 dollars will be given ________ can find the lost child.
.So often ______ in recent years that it has almost become a rule.
.The farmer who admitted ______ the tiger was severely punished.
.They ______ be at home. You see, the door is locked from the outside.
.Our English teacher had us all _______our names on a card.