Greetings, jf.

I used the CD-version of Knoppix 7.0.5 to make my LiveUSB.
As Werner says, Chromium is not on the 7.0.5 Knoppix CD, per se.
I've added Chromium to my LiveUSB using Synaptic, but that was
some months back.

Since Debian has just re-arranged the apt-get material, I expect
it may not be _easily_ possible to _now_ 'just bring it in with Synaptic'.
At the present time, Knoppix 7.0.5 Synaptic repo designations may
not be reliable because of the recent Debian change.
Knoppix repo designations are always somewhat hard to understand,
maybe especially so now.

Some easier options _right now_ are either
1. Just wait a little longer (presumably days) for Knoppix 7.1; or
2. See if a 7.0.5 LiveDVD will serve your purpose.