12. -- Why didn’t you come to see the film with your parents last weekend?
-- I _____ my lessons for the month- exam.

Linyi isn’t what it used to be. The last decade_______great changes in the city image.

----- Did you visit her while you _____ in New York?
----- I _____ to, but I was extremely busy.

With more forests being destroyed, huge quantities of good earth _____each year.?

I'd like to have visited the Palace Museum last week, but something unexpected _____to my father.?

He started early so that he_____there in time.

If you_____this experiment you will understand the theory better.

I don’t like to be interrupted if I_____.

I wonder if he_____us, and I think if he_____us we’ll be able to complete the task ahead of time.

— The floor is too dirty.
— I know.  It  _______ for weeks.