— What were you and your sister doing when the telephone rang?

— I          while my sister was eating.

A．sleep

B．am sleeping

C．slept

D．was sleeping

在估计可持续增长率时，通常假设内部融资的资金来源主要是( )。

A．留存收益

B．净资本

C．增发股票

D．增加负债