My esteemed friend, partner and co-author has laid it out perfectly for you.
Just follow the instructions table-wise.
One thing that may not be obvious from Peter's prescription is that you need
to enter a bunch of rows into the industry table first, so that the foreign
keys will make sense in the bridge table. But presumably this is not
Over here we commonly use a table called SIC (standard industry codes) that
has sub-industries etc. Whenever possible I try to use such standards rather
than make up a new one. For example, there is the ISO country codes
standard, which provides unique two and three letter codes for every
country. Yes, thanks to politics, envy, revenge instinct etc. such country
codes from time to time require updating, but I choose to stick with the ISO
standards rather than rely on my self-invented one and all attendant hassles
whenever a country commits seppukku.
You might consider looking into the SIC code scheme before bothering to
invent your own. You can download this from a number of sources and in a
number of formats. Just Google SIC and you should get there.
Hope this helps,