1. I am writing to complain about the dirt and smoke which comes / coming from your factory chimneys.
2. Two days ago I decided to do my washing.
3. I washed the sheets and put them out to dry as it as a nice sunny day and there was a breeze.
4. When I took the washing in, I was horrified to discover that it was covered in dirty marks.
5. I assume that the breeze I mentioned carried / must have carried the dirt from your chimneys.
6. If this is the case, I must complain in the strongest possible terms.
7. This is not only because of my sheets but (also) because we have two small children who are made to breathe the same air.
8. Until this incident I thought your chimneys were safe and clean.
9. I must warn you that I am going to write to the local newspaper tomorrow.
10. I look forward to receiving your reply.