超一流化学高手、化学专家请进(Periodicity 0038)

超一流化学高手、化学专家请进(Periodicity 0038)
请用英文解答(该题是要用英文解的答化学题,不是翻译题).
Sulphur dioxide is commonly produced in power stations as a pollutant.It is treated with copper (II) oxide.
(a) Suggest how to regenerate the copper(II) oxide used up in the treatment process.
(b) Copper(II) oxide is also used as a catalyst to treat another gas emitted from a power station with ammonia and air.State the gas.
Thanks.