请根据文章提供语境用恰当的引导词填空.

请根据文章提供语境用恰当的引导词填空.
Dear mom and dad,
I am afraid I have some very bad news for you.My school master is very angry with me _____ I made a big mistake.
The trouble started last night ______ I was smoking in bed. ______ I was smoking I heard footsteps (脚步).I didn't want my teacher to eatch me smoking so I threw the cigarette away.Unluckily,
it was _____ a coincidence (巧合) that the curtain nearby caught fire too.I threw the quilt onto the fire ______ the fire should be put out,but the whole house caught fire at last.
They phoned 119. the school was _____ far from the town that _____ the firemen arrived,the whole school was in flames (火焰).
The master said that the fire was all my fault and you must pay for the damage
I am very sorry about this.
much love,
Sarah
P.S. None of the above is true,but I have failed my exams.I just want you to know how bad things could have been!
把序号也写出来，不然我会糊涂写错。