--- How did you pay the workers?     --- As a rule, they were paid ______.

  A. by hour         B. by the hour     C. by hours     D. by an hour

 How did you pay the workers? As a rule, they were paid ______.
  A. by an hour     B. by hours           C. by a hour         D. by the hour

-How did you pay the workers?

-As a rule, they were paid ________.

A．by hour        B．by the hour       C．by an hour        D. by hours

--- How did you pay the workers?     --- As a rule, they were paid ______.

—How did you pay the workers?

—As        rule,they were paid by        hour.

A.the;the  B.a;an   C.a;the   D.the;an