Passage 1
When the natural climate changes due to global warming,it can surely affect seals.The majority of them live in the Antarctic region but the ice is melting and their natural habitat can be seriously affected.These changes don’t take place overnight.They can be the result of many years of additional temperatures in the area.The seals then have to find ways to adapt.
Seals depend on the cool air currents to bring plenty of food for them.When the temperatures get higher there is less and less food and the seal population starts to shrink.Mothers are not healthy enough to feed their babies.Many of them end up abandoned as the mothers have to leave to find their own source of food.
The fact that their desire to produce young can be changed and the warmer temperature is frightening too.It is also believed that the warmer temperature can allow different diseases and viruses to attack the seals.This is a huge concern as they can rapidly wipe out huge numbers of seals out there.
However,these changes in climate and temperature aren’t all bad for other species of seals.Scientists have found that those living in warmer climates are producing more young due to the changes.Research also shows that the females are moving further to find food and water.When they are out of the reach of the governing males,they are more willing to accept the moves of other males in the group.
This is good news too because it means that there will be more selection in the gene pool(基因库)for future generations.It can help the seals as a species adapt to change in their natural environment more easily.
The climate change problem for seals is directly linked to humans.When we take action to change what we let out into the environment,we will make positive changes for the seals.However,it is going to take a very long time to reverse (彻底改变)the effects of what has already been done.
【语篇导读】本文是说明文,主要介绍了气候变暖对生活在南极地区的海豹的影响,
1.What does the author regard climate changes for seals as?
A.A double-edged sword.
B.An unavoidable disaster for existence.
C.A mirror of evolution.
D.A requirement for more choice in the gene pool.
2.What will happen to the seals in warmer climates?
A.Their number will be on the increase.
B.The female seals will be in the lead.
C.Their genes will change a great deal.
D.The females will keep away from the males.
3.Which of the following can be the best title for the text?
A.The Importance of Protecting Seals
B.Seals’ Adaptation to Climate Change
C.How Climate Change Affects Seals
D.Why Are Seals Becoming Less and Less
Passage 2
If you thought pilots dimmed(调暗) the lights before takeoff to give you some shuteye,think again.Believe it or not,the dim lighting could actually help save your life in case of a plane emergency.
The dimmed lights before taking off from the runway and landing are a flight precaution used to help passengers’ eyes adjust more quickly during an emergency escape.“Going from a brightly-lit environment to one that’s completely dark would require some time for our eyes to focus and see the escape slide,”Alice Theriault,service director for Air Canada wrote in a press statement.“Since we need to have all the seconds on our side in the event of an emergency,dimming the lights is one of many steps we take to ensure the safety of our customers.”
The phenomenon that your eyes see those strange speckles (小斑点) as your sight adjusts to a dark place after being in a light place is called dark adaptation.It normally takes our eyes about 20 to 30 minutes to see best in a dark room.The brighter the lights,the longer it takes for our eyes to adjust,which is why dimming the plane lights could shorten your “dark adaptation” time since you haven’t been sitting under fluorescent bulbs (荧光灯) all flight.
Not only does dimming lights add valuable time to the escape process,it also reduces the tension on your eyes if you need to look outside,or see the emergency lighting along the passage.“It helps keep you in the right direction,” Patrick Smith,an airline pilot and author of Cockpit Confidential told The Telegraph.“It also makes it easier for flight attendants to assess any outside risks,such as fire or debris,that might affect an escape.” So next time a pilot dims the lights,just know it’s for your safety,even though it creates a gentle atmosphere for your takeoff into the sky.
1.The lights are dimmed before takeoff to help passengers .
A.take a short break
B.escape in time of emergency
C.create a warm atmosphere
D.adapt their eyes to the bright environment
2.What is one of the roles of shortening “dark adaptation” time?
A.Slowing down the landing.
B.Adjusting the plane lights.
C.Keeping passengers calm.
D.Helping the crew judge outside risks.
3.What does the underlined word “It” in the last paragraph refer to?
A.Dimming lights. B.The escape process.
C.Reducing tension. D.The passage.
4.What is the text mainly about?
A.A tip of air travel.
B.An emergency event on a plane.
C.A warning message on a plane.
D.An explanation of an airline safety measure.
热点推荐：
公共英语等级考试PETS1-PETS5模拟试题汇总（680套）
公共英语不用盲目备考，网校教研团队精心打造高通关套餐班，密训锁分，保障快捷通关!2020年公共英语锁分套餐班强势推出，精锐老师分题型专项辅导，听说读写稳步质变>>课程试听！
加入公共英语考试群676310221 
有专业的老师为您解答问题，还可以和考友一起交流！
赶紧扫描下面二维码！！！
