.----Who are those people gathering in front of the building? -----A group __________ itself the youth volunteers.
This took place in the ______ .
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.