$$2008-AMC10B-18$$  Bricklayer Brenda would take $$9$$ hours to build a chimney alone, and bricklayer Brandon would take $$10$$ hours to build it alone. When they work together they talk a lot, and their combined output is decreased by $$10$$ bricks per hour. Working together, they build the chimney in $$5$$ hours. How many bricks are in the chimney?  瓦工布伦达单独建造一个烟囱需要花费 9小时，而瓦工布兰登单独建造它需要花费 10小时。 当他们一起工作时，他们会说很多话，他们的总效率每小时减少 10 块砖。 他们一起工作，在 小时内建造了烟囱。 烟囱里有多少块砖？
选项为:A:$$500$$  B:$$900$$  C:$$950$$  D:$$1000$$  E:$$1900$$  请回答其中一个选项.