—Did you meet the professor at the airport?—No,he ____ by the time I ____ there.
We don't have_______ salt at home. Could you go and get _______, please?
—Excuse me, when is the Christmas party of our school? —This year, it's_______18:00_______ Monday evening.
---Your schoolbag looks very nice! ---.
--- Where _______ my books? --- ___ on the desk.
I don’t like science _______ it’s difficult.