Question on industry and Food icons

[BYU 14]

Do these provider benefits as long as you control the territory they are in or do you need units in their HEX, I know a syupid question, but I want to verify I am getting the most out of them.

[micha1100]

Controlling the hex is enough. However, you can never control enemy industry (it always gets destroyed when you take the hex) and you need to have three enemy food hexes in order to produce one food item for you.