We have developed gradually to resist them, and in response they have developed new ways of infecting us. We have had antibiotics(抗生素) for almost a century, ever since Alexander Fleming discovered penicillin. In response, bacteria have responded by developing antibiotic resistance. The battle is endless: because we spend so much time with pathogens(病原体), we sometimes develop a kind of natural situation where we can’t make progress. However, what would happen if we were suddenly exposed to deadly bacteria and viruses that have been absent for thousands of years, or that we have never met before? We may be about to find out. Climate change is melting permafrost(冻土) soils that have been frozen for thousands of years, and as the soils melt they are releasing ancient viruses and bacteria that are springing back to life. In August 2016, in a remote corner called the Yamal Peninsula in the Arctic Circle, a 12-year-old boy died and at least twenty people were hospitalised after being infected by anthrax.(炭疽病) The theory is that, over 75 years ago, a reindeer infected with anthrax died and its frozen body became trapped under a layer of frozen soil, known as permafrost. There it stayed until a heat-wave in the summer of 2016, when the permafrost melted. This exposed the reindeer body and released infectious anthrax into nearby water and soil, and then into the food supply. More than 2,000 reindeer eating grass nearby became infected, which then led to the small number of human cases. The fear is that this will not be a single case. As the Earth warms, more permafrost will melt. Under normal circumstances, superficial(表面的) permafrost layers about 50cm deep melt every summer. But now global warming is gradually exposing older permafrost layers. 1．According to the passage we can say _______A.anthrax infected a small number of humans, which led to reindeer casesB.there is a heat-wave every yearC.now global warming is exposing the same permafrost layers.D.the war between humans and bacteria has not been finished.2．When coming to the possibility of being exposed to deadly bacteria that has been absent for thousands of years, the writer thinks ______________A.the possibility is indeed highB.the possibility is lowC.people are being infected nowD.reindeer are being infected now3．If we want to avoid releasing ancient viruses and bacteria, what should we do first? We should _________A.stop developing antibioticsB.deal with global warmingC.control reindeerD.protect rivers4．After reading the passage we may find ________A.the writer is worriedB.the writer is confident.C.the writer knows how to deal with the problemD.the writer thinks highly of bacteria

Throughout history, humans have existed side-by-side with bacteria and viruses. We have developed gradually to resist them, and in response they have developed new ways of infecting us.

We have had antibiotics(抗生素) for almost a century, ever since Alexander Fleming discovered penicillin. In response, bacteria have responded by developing antibiotic resistance. The battle is endless: because we spend so much time with pathogens(病原体), we sometimes develop a kind of natural situation where we can’t make progress.

However, what would happen if we were suddenly exposed to deadly bacteria and viruses that have been absent for thousands of years, or that we have never met before?

We may be about to find out. Climate change is melting permafrost(冻土) soils that have been frozen for thousands of years, and as the soils melt they are releasing ancient viruses and bacteria that are springing back to life.

In August 2016, in a remote corner called the Yamal Peninsula in the Arctic Circle, a 12-year-old boy died and at least twenty people were hospitalised after being infected by anthrax.(炭疽病)

The theory is that, over 75 years ago, a reindeer infected with anthrax died and its frozen body became trapped under a layer of frozen soil, known as permafrost. There it stayed until a heat-wave in the summer of 2016, when the permafrost melted.

This exposed the reindeer body and released infectious anthrax into nearby water and soil, and then into the food supply. More than 2,000 reindeer eating grass nearby became infected, which then led to the small number of human cases. The fear is that this will not be a single case.

As the Earth warms, more permafrost will melt. Under normal circumstances, superficial(表面的) permafrost layers about 50cm deep melt every summer. But now global warming is gradually exposing older permafrost layers.

1．According to the passage we can say _______

A.anthrax infected a small number of humans, which led to reindeer cases

B.there is a heat-wave every year

C.now global warming is exposing the same permafrost layers.

D.the war between humans and bacteria has not been finished.

2．When coming to the possibility of being exposed to deadly bacteria that has been absent for thousands of years, the writer thinks ______________

3．If we want to avoid releasing ancient viruses and bacteria, what should we do first? We should _________

4．After reading the passage we may find ________

A.the writer is worried

B.the writer is confident.

C.the writer knows how to deal with the problem

D.the writer thinks highly of bacteria