The guest ___________ one of the hotel servants of stealing her money when she was out.

A．will enjoy the most efficient and economical air-conditioning device
B．can store up a large amount of winter cold and use it anytime
C．can make full use of winter cold to preserve food in summer
D．may use a bit of winter's chill to help them survive a hot summer

A．how to make enough ice underground
B．how to install the whole device underground
C．how to design the proper heat exchanger pipes for the system
D．how to make the tank so as to keep the temperature