Knowledge is inside the mind, it has no bones and flesh it cannot be seen unless manifested.
What Adam and Eve acquired were actually, GOOD and EVIL spirits.
Good spirits are thoughts and emotions that are good in nature i.e love, patience, peace, wisdom, etc.
Bad spirits are thoughts and emotions that are evil in nature i.e hatred, lies, war, disarray, etc.
When Adam and Eve obtain this knowledge or spirits of good and evil which they plant to themselves. The first knowledge of good and evil they ever manifested were;
1.) Knowledge/Spirit of Evil
Lust- One of the evil knowledge- resulting in covering their body (Gen 3:7)
2.) Knowledge/Spirit of Good
Love- One of the good knowledge- resulted in making love (Gen 4:1)