---Who are you talking _______? ---My good friend, Cathy.
I’m not sure whether I can hold a party in the open air, because it ______ the weather.
Some students are so ______ that they often make mistakes in their homework.
There’s ______ apple on the table. _______ apple is for my little brother.
Anyone who sings well can the activity in our school.
I was told to meet Mr. Green at the airport. But I don't know he will arrive.