It was in the school __________ he had studied ___________ he began the important experiment.
There_________still some milk in the fridge. It’s not necessary to go to the store today.
—_________T-shirt do you like better, the red one or the blue one?—I prefer the red one.
Your English teacher has never lost his temper, _________he?
You had better_________because you have to drive back home.
As we all know, it’s not polite to keep others_________for a long time.