---It is known to all that this factory pours lots of waste water into the Changjiang River every year.---- _________ near my hometown.
About _________of the workers in that steel works are young people.
The workers can complete the new bridge in_________ .
It took me_________days to finish drawing a beautiful horse.
There were_________the students in our class who are from the north.
To plant a tree,we must dig_________ .