My brother bought a computer yesterday. He wants to

learn to use it to help himself get _____  than before. [ ]

A. much organized

B. little organized

C. more organized

D. less organized

疼痛的调控机制中，“中脑PAG、延脑头端腹内侧核群和一部分脑桥背外侧网状结构的轴突经过脊髓背外侧束下行，对脊髓背角痛觉信号传递产生抑制性调控”属于（）

A.认知调控

B.闸门学说

C.下行调控通路

D.内源性镇痛机制

E.GABA能和阿片肽能神经元的节段性调控