You're right. You obviously know Geoff. If you see him, give him my regards. With only two questions to go, all three of your lives are intact - which means you've succeeded. Let's see it out to the very end: here's Question 6.

I was trained to make explosions from washing up liquid, birthday cards, a pipe cleaner, ______ _______.

   battery acid and a watch
   Semtex and a detonator