题目

After a long walk, Mary's legs ________and she couldn't run any further. A．gave out          B．broke out C．tired out         D．stuck out 答案：A（1）解方程：（x-3）2+4x（x-3）=0．（2）解方程：2x2-4x-7=0（3）计算：12+|3-2|+(2-π)0．（4）24-12-2(3-1)．