When we were young, every evening my brother and I ______ stay at home waiting for our mother.

Nanjing isn’t so large __________ Shanghai, however, it’s the second __________ city in East China.

— Must I go to medical school and be a doctor like you，Dad?— No，you__________，son．You’re free to make your own decision．

—Where did you get The Frog written by Mo Yan?—I picked it up from a bookshop online if you ________ know.

The manager demanded that the work________ within three days.