He seems a little .A. sad B. sadly C. sadness
I was doing my homework _______ a dog came in.
—Mary can’t help ___the house. Why? —Because she is busy ____a hotel reservation.
It is about _______by bus from here to Harbin.
It’s impossible for us ____ there on foot in two hours.
—Will you go to Hangzhou by _____ car? —No, I'll take _____ train.