Carl is studying ________ food science at college and hopes to open up ________ meat processing factory of his own one day.
There are ______ in this building , I live on ______.
The water behind the Three Gorges Dams (三峡大坝) should be ______ higher than downstream(下游)。
There are _______ days in a year.
---How many teachers are there in your school? --- __________. , but I'm not sure.
There are _________ doctors and nurses working hard in that hospital.