--- What a beautiful dress ! _____ is it ?--- 200 yuan .
Sunglasses are used ________ protecting your eyes in sunny days.
Leo was late for class again. So he____ clean the classroom after school.
His wife advised him________ drinking, but he wouldn't.
That beautiful skirt is _____ cotton.
— Why _____ most stars _____ in the daytime?— Because the sun is too bright.