---He's seldom late for school,______?

---_____. He is used to going to school early.

A．is he, No

B．has he, No

C．isn’t he, Yes

D．hasn’t he, Yes

( )是指经济运行过程中繁荣与衰退的周期性交替。

A．经济规律

B．经济交替

C．经济周期

D．经济变动