DG＜0 在下列那种条件下可以作为自发过程的判据 A．等温、等压，无其它功 B．等温、等容，无其它功 C．等压、等容，无其它功 D．等熵、等压，无其它功

—Be seted, plesend I’ll mke you cup of te. —_________. Let’s come to the point first.You needn’t do so B．Plese don’t bother C．Youre welcome D．Youre indeed too polite.A．You needn’t do soB．Please don’t botherC．You are welcomeD．You are indeed too politE．

A、关键层
B、紧密层
C、核心层
D、备用层