twelve,twenty-three,thirty-four, (forty-five),(fifty-six)
eleven,thirty-one,(fifty-one),seventy-one,(ninety-one)如果不麻烦的话，请告诉我为什么这样写把它用阿拉伯数字写出来，就会比较容易发现数字间的逻辑： 12 => 23 => 34 => 45 => 56 11 => 31 => 51 => 71 => 91如果还有问题欢迎继续追问