On____cold morning in___October of 2010,we all saw the first heavy snow.
Is this school ____ we visited three years ago?
Is this the school ____ we visited three years ago?
How many students are there in your class ____ homes are in the country?
Alice received an invitation from her boss, ____ came as a surprise.
The train was crowded and I had to get into a carriage ____ already seven other people.