单项选择题
A．because they took place at night B．as a signal for the crowd together C．to limit the time when offers could be made D．to keep the auctioneer warm
A．for the highest price offered B．only at fixed prices C．at a price less than their true value D．very cheaply
A．he sometimes wants to confuse the buyers B．he knows from experience that certain people will want to buy certain items C．he wants to keep certain people waiting D．he wants to reduce the number