—How do you like his wife? —She is ______like a good housekeeper, for the children's room is always in a terrible mess. A．somebody B．nobody C．something D．nothing
—Would you mind giving your advice on how to improve our business management? —If you make ______ most of the equipment, there will be ______ rise in production． A．
是等比数列，且
，那么
的值等于