The rock was weathered by water, sand, and other rocks
Yes it is. Since he is of french blood like the others they should consider it. Although reason may not mater to them they should still consider it because he is of french blood.
The subject of the sentence "I read your blog post on the website" is "I". You can find the subject by asking yourself what is the person, place, or thing that is doing the 'doing' or is 'verbed'. Hope this helps! :)
