Frank often wears a mask _____ he can keep fit in the foggy and hazy (霾) weather.
—Did you hear the news about the fire in our building? —Yes. It took the firemen two hours to __________ the fire.
—May I have some juice, Mum? —Sorry, dear. There is __________ left in the fridge. What about some milk?
—Excuse me! You can’t take photos here. Look at the sign. It says “No photos.” —Sorry, I__________ see it and I __________ do it.
Look! There are ___________ people in the shopping mall.
—__________ the way, did you see Mrs Lee __________ your way here? —Yes. She was waiting for a bus.