What are you looking ______? -My watch. I can’t find it now. Have you seen it anywhere? [ ]

Have you returned the book to the library _______?—Yes, I have _______ retuned it.

people come to visit the Great Wall every year.

Shanghai Waihuan Tunnel is already open to traffic, so it will take us ______ time to go to Pudong International Airport.

How long did you stay at the party?— I only stayed there for ________ hour.