An example of such jobs would be Mining and being a Pharmacist. Miners would often inhale dirt and other components that would destroy their lungs, while pharmacists would inhale fumes and other matter that's bad for you. The same can go for Construction workers who would inhale a large amount of dust.
False. Arteries transport blood in-out. Out-in are veins.
According to research, there are many fluids that work to hydrate the body .apart from water, milk is a good hydrant it helps you to retain a lot of fluids for longer hours. It is also considered to be effective in countering dehydration.
Hot and iced tea also has the same hydrant effects as water and they do contain antioxidants which are quite beneficial for the body.
I don't know if you mean Potty training but it can occur as early as 1 year+ if you are talking about Bathroom training