lol, hell alien i sure mad!!! i dont know if alines are most prized or not, but i KNOW the pred armor is not acid resistance... becasue we never seen preds fight aliens, so we dont know, but about the wristblade thing, i think it's for human, and the spear is for aliens so they wont get hurt by the acid. and the intellgence thing, if they are smart and invent acid-resistence armor, they would smart to make bullet-proof armor too, but they didnt.(Predator Movie 1) And in Predator 2, the Elder give a 1757 pistol to Danny!!! that's before United States was born!!! that's enough time to develop bullet-proof armor!!!