题目

—Today is Sunday！____ —I usually clean my room. A . Where do you usually go on the weekend? B . Why are you shopping today? C . What do you do on the weekend? 答案：C已知二元一次方程：（1）y=x-2；（2）x+y=4；（3）2x-y=2．请从这三个方程中选择你喜欢的两个方程，组成一个方程组，并求出这个方程组的解．所选方程组：______