.---I’m sorry, but there’s no smoking room in this section on the train. ---Oh, I _____ that, and I won’t smoke again.
Tough ______ _money, his parents managed to to send him to a key university.
She ____________ the path as the trees around her became thicker.
Once ________ more attention, the little trees could have grown better.
After ten hours’ operation, the doctors managed to _____the one-year-old twins at the head.
It remains______ whether the medicine has side effect.