有關partial agonist 的敘述，下列何者正確？
partial agonist 對受體的binding affinity小於full agonist
partial agonist 對受體的intrinsic efficacy小於full agonist
partial agonist與full agonist一起合用時efficacy會相加成
partial agonist較full agonist不易受拮抗劑的抑制
