I'm so glad to see you back,Lucy. How long at your grandma's?
He _______ busy yesterday, or he _______ you with your experiment.
A teacher of English and class teacher _______ us something about volunteer workers.
It every day so far this month. I can't tell you if it tomorrow.
A student of Fudan University ___ Huang Yang, was reported ____ by his roommate, ______ the whole nation.
---Jack, you erase the blackboard today, __________? ---But I did it yesterday.