—Who helped Mark with his English?—_________, he taught himself.
It’s________to play on the road.You’d better play in a________place.
There are so many kinds of pens in the shop that I can’t decide________.
—Excuse me,could you tell me________a book about science?—Sure.They are on the second floor.
A________day!Don’t you want to go out for a walk with us?
I hear it’s a________experience to visit the caves and many people go there every day.