在一条平直的公路上，甲、乙两辆汽车沿同向行驶，甲车以20m/s 的速度做匀速运动．当乙车在甲车前84m处时，乙车速度为4m/s，且正以2m/s²的加速度做匀加速运动，经过一段时间后，乙车的加速度突然变为零．已知经过12s后两车相遇．求乙车加速行驶的时间．

用方框中所给单词的适当形式填空, 使短文意思完整、通顺。

    Before graduation, many classmates were busy ____ for jobs. So was I. It was very difficult to find a job in the big city. I had been ____ for many times until I found a want ad for an editor. “If you could find ____ than 10 wrong words in the newspaper, you can work ____ an editor,” the ad said. I loved literature(文学) and had written several little ____ for the newspaper. So I decided to have a try. It was the final date when I saw the newspaper. I told one of my roommates the news happily. After he ____ the news, he smiled and said “Today is April Fool's Day. It may just be an April Fool's ____. A fool may take it ____.” I was very disappointed after hearing that, but I still wanted to have a try. It took me the whole morning to find 12 wrong words in the newspaper. I ____ at the editorial department in the afternoon and got the job immediately.

    Later I knew I was the only applicant(申请者).I got a lesson from the experience: Something others said was ____ may be not impossible. As long as you believe it, you may make impossible possible.