No one figured out "unknown parts" which was a reference to how the Chinese are attacking us without us realizing it. Ordinary household equipment has unknown parts that can act alone or in concert with other device or equipment. Example, I bought a carbon monoxide detector at HD for the red noxious gas coming out of my stove, it just made the problem worse. It never detected shit, but the gas is so bad that we have to open windows and turn fans on high to cook quite often. It's that bad, find more, I promise you it's there… That is why POTUS called it out.