Over the past decade, drug-resistant diseases have appeared as a major health threat. But where do they develop the drug resistance? One surprising theory: they may have developed the resistance on farms, and not in hospitals.
The crop protection products farmers use to control many plant diseases are almost the same as the drugs doctors use to treat infections, including fungi (真菌). Fungi are continually mutating (变异), and with a life cycle measured in days or weeks, they mutate quickly. When a mutation produces resistance to a chemical-killing fungi, fungi will jump to any host that provides a welcoming environment, such as a human body. And if the treatment for the fungal infection involves a drug similar to the fungicide encountered on the farm, Fungi may develop quickly in the human body-just as they did in the field.
An obvious solution is to use less fungicide in the field. Reducing fungicide use would not only slow the development of the drug resistance, it would help restore diversity to the fungal world. Fungicides are a must in the farming community. Plant diseases pose a major problem for farmers globally-in some crops, disease can reduce harvests by more than 70 percent-and failure to deal with the problem can mean financial ruin.
Just like Fungi-or, indeed, any living thing-plants continually evolve. This is how natural gene editing (基因编辑) works, and without it, we'd all still be single cells in a salty soup. Through natural selection, almost any plant will eventually produce resistance to Fungi. But this can take centuries, so we don't have the time to wait.
On the other hand, advances in genetics have given us an understanding of nature's gene editing process in plants, helping us develop resistance to a disease. Gene editing techniques can then enable us to produce disease resistance-just as nature would do, if given enough time.
1.What can we infer about Fungi from Paragraph 2?
A.They can treat infection sometimes.
B.They don't stop developing new forms.
C.A human body is their favorite place.
D.There are no Fungi in the fields now.
2.Which of the following can replace the underlined word ''pose'' in paragraph 3?
A.Solve. B.Face.
C.Cause. D.Overcome.
3.What makes a plant produce resistance to Fungi?
A.The survival of the fittest.
B.Advances in technology.
C.The use of farm chemicals.
D.A welcoming environment.
4.What can be the best title for the text?
A.Ways to Prevent Drug-resistant Diseases
B.The Source of the Drug Resistance
C.The Popularity of Gene Editing Techniques
D.The New Theory of Natural Selection
Road networks are expanding worldwide at an alarming rate. Although roads can promote economic development and improve human welfare, they can also have severe effects on wildlife populations by worsening habitat and human disturbance. Moreover, traffic disturbance from noise, lights, and motion reduces the quality of habitat near roads.
While roads are now everywhere across much of the earth, the construction of new roads will be concentrated in areas with high biodiversity value. Many of these new roads and highways will likely cross reserves or other highly biodiverse areas. Although roads are one of the most important impacts on global ecosystems, we know little about how patterns in road construction will affect biodiversity in the coming decades.
Here, we use a recently developed global roads data set to investigate the extent and potential influence of road networks across the 1,160,000-km,13-country range of the globally endangered tiger. In the Russian Far East, for example, roads reduce tiger survival rates due to crashes into vehicles. In some regions, tigers avoid areas closer to public roads, suggesting that roads act as important barriers to movement. The emerging impacts of road development on tigers are critical for several reasons.
We calculate road density (度), distance to the nearest road, and relative mean species abundance (MSA) to characterize how road networks influence tiger habitats. These systems of measurement provide starting points for range-wide monitoring and impact assessments of road development projects, thus enabling evaluation of progress toward country-level conservation and sustainable (可持续的) development goals.
1.What is the second paragraph mainly about?
A.The importance of creating reserves.
B.The destruction to global ecosystems.
C.The effect on biodiversity worldwide.
D.The opinion about road construction.
2.Why is road development attacked?
A.It has bad influence on tigers.
B.It causes more traffic accidents.
C.It covers too many areas.
D.It requires a quantity of funds.
3.How does the author feel about the systems of measurement?
A.Optimistic. B.Doubtful.
C.Concerned. D.Astonished.
4.In which section of a website may the text appear?
A.Entertainment. B.Health.
C.Education. D.Science.
Recently Stiles aged 17 took her 3-year-old brother, James, to her high school. A family emergency prevented her parents from being able to pick up James. So they asked Stiles to step in.
''This was a one-time event; we have never had her get him from school other than this day But it was an emergency, '' her mother said. ''I figured she had gone to get him and taken him home Later that day I saw the picture online and realized that she had taken him back to school. ''
Little James quickly fell asleep in his big sister's arms at the high school.
She didn't want to be counted absent or miss any work. Stiles was studying to be a nurse. She was in her class, and the teacher gladly welcomed her little brother in. He was so tired from his school that he slept most of the class. She not only helped her family out but returned to her responsibility at school.
Her teacher was very supportive and didn't mind him being in the class at all. He slept most of the time and if he had become a problem she would have taken him out. She attends an amazing school that clearly sees the value in family and education.
Her mom said she can now put to rest any worries she's had that the 14-year age gap between Stiles and James would keep them from being close. As a mom, she was thankful that they had this kind of relationship, and she prayed it would always stay this way.
1.Why did Stiles' parents ask her for help?
A.Her family had an emergency.
B.Her parents couldn't collect James.
C.Her brother refused to attend school.
D.She was close to being an adult.
2.Where did Stiles want to work when she grew up?
A.In a hospital.
B.In a school.
C.In a factory.
D.In a shop.
3.What was Stiles' teacher's attitude to her act?
A.Opposed.
B.Critical.
C.Ambiguous.
D.Supportive.
4.What once made Stiles' mother concerned?
A.Stiles' identity of being a senior high student.
B.Stiles' terrible relationship with her classmates.
C.The age difference between Stiles and her brother.
D.Stiles' bad performance in the key school.
Spending time outdoors can reduce stress and increase overall health. Stuck inside? You can still connect with nature with a virtual visit to a national park. Four of the most visited national parks in the nation offer creative ways for visitors at home to explore its beauty.
Grand Canyon National Park
On a Grand Canyon virtual archaeological tour, armchair travelers get an inside look at the first major archaeological site along the Colorado River in nearly four decades. A series of interactive 360-degree photos show the archaeologists (考古学家) at work, with insight into their tools and methods.
Yosemite National Park
Few national parks have more natural wonders than Yosemite. Visitors can see water pouring down from Yosemite Falls or look up at Half Dome from the floor of Yosemite Valley.
Olympic National Park
Olympic National Park protects a rainforest ecosystem (生态系统) largely untouched by human habitation. It also protects an incredible range of habitats and impressive biodiversity (生物多样性).
A set of beautiful interactive wall paintings appeals to those with an interest in plants and animals. Click through the images to learn more about what’s growing in the park.
Yellowstone National Park
America’s oldest national park is also one of the easiest to tour virtually. You can watch Old Faithful erupt in real time or send an audio postcard featuring the sounds of springtime, the barks and howls of wolves at Blacktail Pond.
1.What is special about Grand Canyon National Park?
A.It provides a wide range of photos for tourists.
B.It offers travelers chances to act archaeologists.
C.It makes visitors understand archaeological tools.
D.It has a history of approximately forty years.
2.What attracts tourists most in Olympic National Park?
A.The rainforest ecosystem.
B.Attractive wall paintings.
C.Various amazing habitats.
D.Impressive natural wonders.
3.Which park do you choose to hear nature in spring?
A.Grand Canyon National Park.
B.Yosemite National Park.
C.Olympic National Park.
D.Yellowstone National Park.
听下面一段独白，回答以下小题。
1.Why did the speaker buy a new umbrella?
A.His old one was damaged. B.He really loved that one. C.He failed to bring one.
2.What is the main advantage of the hotel’s location?
A.It is beside the Eiffel Tower.
B.It is very close to a bakery.
C.It is within walking distance to Louvre.
3.Why did the speaker go to Paris?
A.To see some artworks.
B.To eat some French food.
C.To meet some good friends.
听下面一段较长对话，回答以下小题。
1.Where does the conversation take place?
A.At school. B.At the zoo. C.At an amusement park.
2.Why is Lisa surprised?
A.John was busy. B.John arrived late. C.John changed his mind.
3.Why did John lie to Lisa?
A.He wanted to come alone.
B.He was afraid of roller coasters.
C.He wanted to give her a surprise.
4.What does John say about Lisa?
A.Considerate. B.Brave. C.Reliable.
