Many cities issued a warning of air pollution for PM-2.5 readings, which became Concern of all the people
He said he ____ an American before.
Eight students ____ ten in our class are League members.
----- When are you _____ your next exams? ----- Next month.
The book-store _____ open until 8 at night every day.
This task is _____ for us. We need ______ people.