A nervous looking woman with red-hair is working with possibly dangerous materials in a lab .
It is impossible that a woman is nervous about using these dangerous chemicals because she 's had a previous accident .
It is impossible that a woman is nervous about using these dangerous chemicals because she 's had a previous accident .
There is a better than even chance that a woman is nervous about using these dangerous chemicals because she 's had a previous accident .
A woman is nervous about using these dangerous chemicals because she 's had a previous accident .