Sunglasses are used ________ protecting your eyes in sunny days.
______Lily ______Lucy may go to the concert because they have got only one ticket.
I noticed him _________ the teacher’s office just now.
I’d like to go _________on vacation.
–I wonder if it _________ tomorrow. –Don’t worry. If it _________, we’ll stay at home.
We learned in geography class that the earth __________around the sun.