- I see you go running every morning.

- Yes. To lose weight, I decide to exercise _______. Wish you good luck!

A．finally

B．regularly

C．secretly

D．quietly.

两个电源的外特性曲线如图所示，由图可知

A．电源a的内电阻较小，电动势较大

B．电源a的内电阻较大，电动势较大

C．电源b的内电阻较小，电动势较大

D．电源b的内电阻较大，电动势较大