题目

Half a year before graduation from college, my son began to seek a job.    36    the financial crisis, fewer companies would like to    37    new staff. My son targeted a company that was    38   to hire only one person    39   there were more than twenty people filling their resumes.After the interview, there would only be 3 who could enter the final round, which would later   40   one person to be employed. Everything seemed to go quite    41   and my son passed the first round and entered the final round in a week.On the day of the final interview, my son and 13、椭圆，双曲线和抛物线，它们都是到定点的距离与到定直线的距离之比为常数 的点的集合（或轨迹）．