1.Why don't we
2.(1)cost me (2)paid for
3.between
4.for时间段,since时间点
he has worked for 3 hours.
he has been working since 3 o'clock.
1.Why don't we
2.(1)cost me (2)paid for
3.between
4.for时间段,since时间点
he has worked for 3 hours.
he has been working since 3 o'clock.