NEW YORK -- Zhao Yu Zhen lives in an apartment on Ash Avenue in Queens, but it's hard for her to get in the building. "Every time, I can't get in," she said in Chinese. "There's no key." Since Zara Realty took over their building in Flushing, she and her neighbors say they're asked to produce birth certificates, marriage licenses, even high fees for access to their own homes. In some cases, a family of five is given only one key to the entrance.