it will expand as water moves into it.
The steel rods will enable the concrete to form without any bumps and it will add shape to the cement and strength, so no odd massive lumps are formed.
That is what I think anyways :)
Awnser: C. petrolium
See, petroleum (i.e. oil) is transformed into gasoline.
"Sometimes, petroleum and crude oil are used to mean the same thing, but petroleum itself is a broad range of petroleum products including crude oil itself. We use the term 'petroleum products after crude oil is refined in a factory." - <span>www.eschooltoday.com/energy/non-renewable-energy/what-is-petroleum.html</span>
