从甲盐库取出的盐运到乙盐库，这时两个盐库所存的盐质量相等，原来甲盐库和乙盐库的存盐质量的比是（ ）。

(单选题)12.（ ） (单选题)11.（ ） (单选题)All the following participles functions as an attributive ex (单选题)Which of the following sentences express “probability”? (单选题)John’s not been to New York, ______. (单选题)Somebody is knocking at the door; I wonder who ______ is. (单选题)Reading can satisfy ______ hunger that comes from the desire (单选题)He is a student of Tsinghua University, majoring ______ phys (单选题)方程组表示的是（ ）。 (单选题)曲线在点处的切线方程是（ ）。