单项选择题
Questions 22 to 25 are based on the conversation you have just heard.
A．In two weeks. B．In three weeks. C．In the second half of her course. D．Not decided yet.
A．They are only charged for the amount of power they consume on rainy days. B．They needn’t pay a single cent for their power consumption on sunny days. C．They only pay for the excess power that flows into the utility’s power grid. D．They pay for the electricity from the grid less their home-generated power.