Social control refers to processes by which ______.

A．norms are developed

B．norms are enforced

C．people are educated and trained

D．people are rewarded and punished

在SPECT脑灌注显像中脑梗死灶显示灌注减低区较X线CT（）

A．范围小，但发现早

B．范围大，且发现早

C．范围大，但发现晚

D．范围小，且发现晚

E．范围一样，但发现早