(2013 ·安徽省级示范高中名校联考)—Hello! Friendship Hotel.Can I help you?

—Do you have a room with a double bed ________ for Saturday?

A．available

B．empty

C．possible

D．useful

过滤槽过滤麦汁时，若压差上升，说明麦糟阻力上升,则必须降下耕糟机，松动麦糟。