—I meant ______ you to the host at the party, but I forgot. —That’s all right. Some other time, maybe.
Apples are usually sold by ________ weight and eggs are sometimes sold by ________ dozen.
—What about ____ book? —It’s too difficult ____ book for beginners.
Whenever you are in trouble ,don’t hesitate _____us for help.
It was the longest film we have ever seen ; it ____ three hours..
___ was invented by Grain Bell..