First listen and then answer the question.
Why is the rescue taking so long?
Six men have been trapped in a mine for seventeen hours. If they are not brought to the surface soon they may lose their lives. However, rescue operations are proving difficult. If explosives are used, vibrations will cause the roof of the mine to collapse. Rescue workers are therefore drilling a hole on the north side of the mine. They intend to bring the men up in a special capsule. If there had not been a hard layer of rock beneath the soil, they would have completed the job in a few hours. As it is, they have been drilling for sixteen hours and they still have a long way to go. Meanwhile, a microphone, which was lowered into the mine two hours ago, has enabled the men to keep in touch with their closest relatives. Though they are running out of food and drink, the men are cheerful and confident that they will get out soon. They have been told that rescue operations are progressing smoothly. If they knew how difficult it was to drill through the hard rock, they would lose heart.New words and expressions 生词和短语
Notes on the text 课文注释
1 rescue operations，营救工作。
2 If there had not been a hard layer of rock beneath the soil, they would have completed the job in a few hours．如果不是因为土壤下面有一层坚硬的岩石，他们的营救工作仅用几个小时就可以完成了。
3 As it is，事实上，实际上。
4 they still have a long way to go，他们离钻透还早着呢。
5 keep in touch with，与……保持联系。
6 run out of，用完，用尽。
7 lose heart，失望，丧失信心。