根据汉语完成英语句子。

1. 如果你告诉我他的住址我将非常感激

    I would _____ _____ if you would tell me his address.

2. 直到20世纪20 年代, 阿富汗人和他们的骆驼还在做着这样的工作.

     The Afghans and their camels did this ______ ______ _______.

3. 那是我第二次犯这么严重的错误.

    That was the second time that I _____ ______such a serious mistake

4. 在离开化学实验室之前,确保所有的灯都关上了.

    Before leaving the chemistry lab, _____ _____all the lights are turned off.

5. 那些地震中幸存下来的人们将永远也忘不了他们那可怕的经历.

     Those_______ ________ an earthquake would never forget their terrible experience.

从5张100元，3张200元，2张300元的奥运预赛门票中任取3张，则所取3张中至、少有2张价格相同的概率为( )．