—The classroom is ____ clean ____ it was yesterday.— Sorry, I forget to clean it.
The students don’t know the broken computer.
I don’t know if Mr. Smith ____. If he ___, I will tell you.
He used to __ in a small village, but now he has been used to __ in the big city.
— Could you tell me ______?— Certainly. In half an hour.
If you don’t know the words, you must ______in a dictionary.