According to a UN report,one third of the world population have no _________ to clean drinking water and health care.
It is only _____ from my home to the train station.
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.