---Would you like some tea? ---Yes, just_____.
–Who’s that boy? –Liang Bo. He is _____ very popular singer in Voice of China.
---Where do Tom and John sit ? --- Tom sits __________ of the room and John sits _________ of the room.
---Is Lucy ______ her homework? --- No , she ________ .
--- Shenzhen is a beautiful city. --- Yes. You can see a lot of flowers and trees on ________ of the streets .
-- What can trees do _________ us ? --- They can _________ harmful gases and produce oxygen .