1 . Warming seas across the globe are endangering coral reefs, a key ecosystem that supports marine life to live and thrive. As a possible way to save them from extinction, scientists have recently frozen and revived groups of adult corals for the first time, according to a recent study.
Freezing biological materials, or “cryopreserving” them, refers to keeping them in a deep freeze for long periods without affecting the cells viability (活性), according to the Science Times website.
This method usually cools them to very low temperatures, commonly to-196℃. Since cells would normally die at such a low temperature due to the formation of ice inside, scientists need to monitor the freezing rate and choose the freezing medium carefully.
Researchers in the US experimented with freezing pea-sized pieces of a common coral in Hawaii. After removing the microbes on the corals, they sealed the corals in metal containers filled with a chemical solution that partially dehydrated (脱水) them and helped control ice growth.
When the corals reached a temperature of around -200 ℃, the remaining water in the corals solidified into a glassy form. The corals were still alive, with their life-driving functions becoming extremely slow. After being cryopreserved for a few minutes, the researchers pulled the corals out and placed them in warm water. In two minutes, they started consuming oxygen — a sign of them staying alive.
Previously, researchers had already successfully cryopreserved coral larvae (幼虫), according to a study in 2018. However, the larvae can only be collected when corals spawn (产卵), which happens just a few nights each year. “That’s putting a lot of eggs in one basket,” US marine scientist Liza Roger told Science News.
This breakthrough offers more hope to the worlds corals, said Roger. However, there’s more work to be done. A few days after thawing (解冻), the corals became “stressed out” from the process and were killed by the bacteria they normally live in harmony with. The researchers are working on using antibiotics to help them survive for a longer period of time.
1. What happened to the corals when they were cryopreserved?| A．They died temporarily. |
| B．Their life functions slowed down. |
| C．They remained alive and unchanged. |
| D．They fed on microbes in the containers. |
| A．It is not a reliable solution. |
| B．It needs a large number of eggs. |
| C．It holds promise for restoring corals. |
| D．It requires overly expensive technology. |
| A．Finding a suitable freezing medium. |
| B．Identifying the bacteria on the corals. |
| C．Expanding the collection of coral larvae. |
| D．Maintaining the corals health after thawing. |
| A．Bringing dead corals back to life. | B．Freeze and revive coral larvae. |
| C．Find a way to preserve corals. | D．Study the conditions of coral growth. |
| A．Sunny. | B．Rainy. | C．Cloudy. |
3 . Most of the new diseases we humans have faced in the past several decades have come from animals. The more we come into contact with wild animals, the more we risk a so-called disease “spillover” from animals to humans.
“As people move and wildlife move in response to a changing environment, humans and wildlife and animals will come in contact more regularly,” said Jeanne Fair from the Los Alamos National Laboratory in New Mexico. Fair argues that by shifting animal habitats, climate change will also make the opportunities for disease spillover more frequent. “Everything is sort of shifting and will shift into the future as the environment changes through climate change,” Fair said.
Scientists, including climatologists and epidemiologists (流行病学家) on Fair’s team at Los Alamos, are beginning to model how changes to the climate will impact the spread of infectious diseases. It’s early days for this kind of research, but previous studies suggest that extreme weather has already played a role in at least one outbreak. Scientists say drought and deforestation have combined to force bats out of rain forests and into orchards (果园) in Malaysia to find food. Those bats, a common disease reservoir, then passed the Nipah virus through pigs to humans for the first time in the late 1990s.
“We’re going by the past data to really predict what’s going to happen in the future,” Fair said, “And so, anytime you increase that wildlife-human interface, that’s sort of an emerging disease hot spot. And so, that’s just increasing as we go forward.”
Jeffrey Shaman, head of the climate and health program at Columbia University’s public health school, argues we don’t yet know whether climate change will cause a net increase in infectious disease rates globally. For example, mosquitoes carry disease that affects millions of people across the world every year. As their habitats expand in some parts of the world, they might contract diseases elsewhere. Shaman says what we know for certain about climate change is that it will make it harder to predict where disease outbreaks will pop up.
1. How does climate change affect the spread of disease according to Fair?| A．By breaking animals’habits. | B．By increasing animals’varieties. |
| C．By promoting animals’breeding. | D．By changing animals’living environment. |
| A．Explaining the influence of Nipah virus. |
| B．Proving the harm of bats to human beings. |
| C．Showing the effects of climate change on disease. |
| D．Presenting scientists’early study about the cause of disease. |
| A．Humans should give up studying animals. |
| B．Frequent contact with animals can cause disease outbreaks. |
| C．Disease hot spots will disappear if animals die out. |
| D．Past data can solve the problems in the future. |
| A．Climate Change and Disease Spillover |
| B．Animals’Interaction with Humans |
| C．Early Studies about Extreme Weather |
| D．Scientists’Prediction for Disease Outbreaks |
| A．Sunny. | B．Rainy. | C．Snowy. |
1. What' s the weather like?
| A．Warm and sunny. | B．Cold and cloudy. | C．Snowy. |
| A．The man himself. | B．The woman. | C．Fred. |
| A．In the morning. | B．At home. | C．In the evening. |
1. What' s the weather like?
| A．Warm and sunny. | B．Cold and cloudy. | C．Snowy. |
| A．The man himself. | B．The woman. | C．Fred. |
| A．In the morning. | B．At home. | C．In the evening. |
| A．It’s cold. | B．It’s nice. | C．It’s warm. |
