小明家电能表上月底的示数为0 8 1 1 6，本月底的示数如图所示，他家本月消耗的电能为　 　kW．h．若按0.5元/（kW．h）计费，本月应付电费　 　元．他家同时使用的用电器总功率不得超过　   　W．

It is very kind of you to do the washing-up, but you    it.

A．mustn’t have done

B．wouldn’t have done

C．mightn’t have done

D．didn’t have to do