6. (2018齐齐哈尔)He has failed ________ times, but he won't give up a ________ chance.
A. third, four  　　B. three, fourth  　　　　C. third, fourth
6. B【解析】考查基数词与序数词。句意：他已经失败次了， 但是不会放弃机会。基数词three 修饰times，第二空考查“不定冠词＋序数词”表示“又一，再一”，故选7。