Frank often wears a mask _____ he can keep fit in the foggy and hazy (霾) weather.
What________ your school life_________ ?
I read an article _______ Mo Yan from China.
Don’t watch TV __________.It’s not good for your eyes.
Mr. Liu often makes us__________in his class, so we all like him.
---Is there ___________ left in the fridge? ---Only some eggs.