Fred entered without knocking and, very out of breath, sank _________ a chair.
He has a part - time job and was paid___________.
The sunlight came in____________ the windows in the roof and lit up the whole room.
The harder you work,____________.
--Do you like the material? --Yes, it ___________ very soft.
--Where is Xiao Wang? --I don't know. He__________ be in the library.