-What were you doing at 7:00 yesterday evening, Lisa?
-I ________ up the kitchen with my mother.
clean
cleaned
was cleaning
am cleaning
How many states _______ the United States? Fifty.
My mother is strict both _____ me and ____ her work.
------ Do you know where Li Ming is working _____? ------ Maybe in Guangzhou, I think.
You should keep working hard ____ you have passed the exam.
Li Ming is in poor health. He should pay more attention _________ exercise.