题目

阅读理解 The summer holiday is over, and finally it'stime to start thinking about going back to school. For some, it's a veryexciting time. For others, however, they can feel very stressful. There arelots of things to do if you want to have a great first day at school. Stay busy throughout the summer holiday.Usually those who struggle (挣扎) on their first days are peoplewho spend too much of their summer holiday indoors and relaxing. So you shouldtry to stay active and busy over the course of the holiday. There are lots ofthings you can do, such as getting a summer job or taking up a sp为何值时，直线（a-1）x-2y+4=0与x-y-1=0（1）平行；（2）垂直。