He’s not a perfect child. He sometimes talks back ____ his parents talk with him.

— I hear the famous singer Xu Song may come to Ningbo next month.— Really? _______ he comes, my younger sister will be very excited.

    --- Hurry up! The bus is coming.--- Wait a minute. Don’t cross the street        the traffic lights are green.

Nothing can be done _______  he returns.

—_____ does your brother go online?  —Let me see. Maybe two or three times a week.