北师大版高中英语新教材(选择性必修第一册)课文 （Unit 3 | LESSON 1)
Lesson 1 The Sixth Extinction第一课 第六次灭绝
Extinctions, where entire species are wiped out, are not unusual in our Earth’s history. In fact, over 90 percent of all species that ever lived are now extinct. In the last 500 million years, there have been five times when life on Earth has almost ended. These include the third mass extinction, known as the “Great Dying”, which killed 90% to 96% of all species. And the fifth event, which
occurred 66 million years ago, caused the death of the dinosaurs. The reasons for extinctions are varied. According to scientists, they include volcanic eruptions, asteroids hitting the Earth from space, changes in sea levels, the decrease of the oxygen content of the sea and global warming. Many scientists say we are now entering the Earth’s sixth mass extinction. This time, human activity will be to blame.
物种灭绝，即某个物种的完全消失，在地球的历史上并不罕见。事实上，曾经存在的物种中
90%以上现在都已经灭绝。在过去的五亿年中，地球上出现过五次生物几乎全部灭绝的情况。这其中包括称为“大灭绝”的第三次灭绝，期间90%至96%的物种灭亡。6600万年前发生的第五次灭绝导致了恐龙的灭亡。灭绝的原因各不相同，科学家认为原因包括火山爆发、小行星从太空撞击地球、海平面变化、海洋氧含量下降和全球变暖。许多科学家认为地球的第六次大灭绝即将来临，这一次，人类活动是主要原因。
Although it is not unusual for species to die out naturally, the rate at which this is now happening is cause for concern. A 2015 study by scientists who were based at Brown University and Duke University in the US, looked at how quickly species die out due to natural causes, that is, the
“background extinction rate”. They found that human activity is causing species to die out 1,000 times faster than normal. There is a long list of reasons why so many species are dying out: air and water pollution, forests being destroyed, factory farming and overfishing. It is clear that human activity has negatively affected all other species on Earth, including animals and plants.
虽然物种的自然灭绝并不罕见，但现在灭绝的速度让人担忧。2015年在美国布朗大学和杜克大学的科学家进行的一项研究，调查了物种自然状态下灭亡的速度，即“背景灭绝率”。他们发现人类活动导致物种灭亡的速度比正常情况快1000倍。这么多物种正在消亡的原因有很多：空气和水污染、森林被毁、工厂化畜牧和过度捕捞。显然，人类活动对地球上所有
其他物种产生了负面影响，包括动物和植物。
If a sixth mass extinction occurs, scientists who have studied the issue believe that up to three quarters of all species on Earth could die out. Of course, as we humans depend on so many species for our survival, we would also be at risk of dying out. Our world and our lives depend on the balance in nature between animals and plants. Without forests, we would have no air to breathe, and without clean water we would be unable to survive.
虽然物种的自然灭绝并不罕见，但现在灭绝的速度让人担忧。2015年在美国布朗大学和杜克大学的科学家进行的一项研究，调查了物种自然状态下灭亡的速度，即“背景灭绝率”。他们发现人类活动导致物种灭亡的速度比正常情况快1000倍。这么多物种正在消亡的原因有很多：空气和水污染、森林被毁、工厂化畜牧和过度捕捞。显然，人类活动对地球上所有
其他物种产生了负面影响，包括动物和植物。 第一汽车
Can a sixth extinction be avoided? Experts say that it is not yet too late, if we take action now. This would mean we have to significantly change the way we live. For example, we need to take steps to save endangered species, including setting up special areas where plants and animals can be protected. We need to change how we work and travel by using cleaner, more natural sources of energy, such as wind and solar energy. We also need to improve our farming methods to reduce water, air and land pollution. In short, if we want to survive, we need to stop destroying the planet that we live on and start to protect it.
第六次灭绝可以避免吗？专家说，如果我们现在采取行动还为时不晚。这意味着我们必须极大地改变生活方式。例如，采取措施拯救濒临灭绝的物种，包括建立动植物的特殊保护区。通过使用更清洁、更自然的能源来改变我们的工作和出行方式，例如风能和太阳能。我们还需要改进耕作方式，减少水、空气和土地污染。简而言之，如果想要生存，就需要停止破坏我们生活的星球并开始保护它。
The Black Robin黑知更鸟
Black robins are the birds that humans saved from extinction. In 1980, there were only five black robins left in the world. They all lived on a small island off the coast of New Zealand. Only one of those birds, a female called Old Blue, was able to lay eggs. Wildlife workers began a programme for raising black robin chicks. They protected Old Blue’s eggs, helped them to hatch, and took care of the chicks. Thanks to their efforts, there are now more than 250 black robins, and the population is spreading. To help them survive, people are restoring their habitats and removing small animals that hunt them, such as mice and cats from the islands where they live.
黑知更鸟是人类从灭绝危机中拯救出来的鸟类。1980年，世界上只剩下五只黑知更鸟。它们栖息在新西兰海岸附近的一个小岛上，其中只有一只名叫老蓝的雌鸟能够产卵。野生动物工作者开始了一项黑知更鸟繁殖计划。他们保护老蓝的蛋，帮助孵化并照顾幼鸟。由于他们的努力，现在黑知更鸟已超过250只，而且数量还在增加。为了它们的生存，人们正在恢复黑知更鸟的栖息地并移除捕杀它们的小动物，例如岛上的老鼠和猫。