【推荐1】What is the Great Pacific Garbage Patch?

The Great Pacific Garbage Patch (GPGP) is the largest of the five offshore plastic accumulation zones in the world’s oceans. It is located halfway between Hawaii and California.

PLASTIC __________

It is estimated that 1.15 to 2.41 million tonnes of plastic are entering the ocean each year from rivers. More than half of this plastic is less __________than the water, meaning that it will not sink once it encounters the sea.

The strong and floating plastics show resiliency(韧性) in the marine environment, allowing them to be transported over __________distances. They persist at the sea surface as they make their way off shore, transported by converging (汇聚的) currents and finally accumulating in the patch.

Once these plastics enter the gyre（环流）, they are unlikely to leave the area until they __________into smaller microplastics under the effects of sun, waves and marine life. As more and more plastics are discarded into the environment, microplastic __________in the GPGP will only continue to increase.

LOCATION

Due to seasonal and interannual variabilities of winds and currents, the GPGP’s location and shape are constantly changing. Only floating objects that are __________influenced by currents were likely to remain within the patch.

By simulating concentration levels in the North Pacific, the researchers were able to follow the location of the patch and found on average it orbits around 32°N and 145°W. However, the team observed seasonal __________from west to east and substantial variations in latitude（纬度）depending on the year.

IMPACT ON WILDLIFE

Plastic has increasingly become a very common substance in the ocean. Due to its size and color, animals __________the plastic for food, causing malnutrition; it poses entanglement（缠绕）risks and threatens their overall behavior, health, and existence.

Studies have shown that about 700 species have encountered marine debris, and 92% of these __________are with plastic. 17% of the species affected by plastic are on the International Union for Conservation of Nature Red List of Threatened Species.

IMPACT ON HUMANS AND SOCIETY

Once plastic enters the marine food web, there is a possibility that it will contaminate the human food chain as well. Through a process called bioaccumulation, chemicals in plastics will enter the body of the animal __________on the plastic, and as the feeder becomes prey, the chemicals will pass to the __________—making their way up the food web that includes humans. These chemicals that affected the plastic feeders could then be __________within the human as well.

__________, yearly economic costs due to marine plastic are estimated to be between $6-19billion USD. The costs __________its impact on tourism, fisheries and aquaculture, and governmental cleanups. These costs do not include the impact on human health and the marine ecosystem due to __________research available.

【推荐2】Nothing seems more inevitable than aging and death-not even taxes. Every plant, animal and person you have ever seen will _______ die. But some recent research suggests that aging as we know it may not be inevitable. Indeed, as our _______ of it grows, aging can be seen not as an unchangeable reality from which there is no escape, but as the product of biological processes that we may be able to _______ someday.

We already know that some animals do not seem to age. Many cold-water ocean fish and some amphibians（两栖动物）never _______ a fixed size: they continue to grow bigger, to be able to reproduce and to live until something kills them. What these creatures seem to be telling us is that something in their _______ —and possibly in ours——controls the pace of aging, _______ that aging is not the fate of every living thing.

Throughout the history of life on earth, one of the most common difficulties that animals and their cells） have faced has been a lack of food. About 70 years ago, scientists discovered that when animals are forced to live on 30 to 40 percent fewer calories than they would _______ eat, something unusual happens; they become _______ to most age-related diseases --cancer, heart disease, diabetes —and live 30-50 percent longer. Restricting calories _______ aging. But what are the ________ genes that preserve vitality and starve off diseases?

About 15 years ago, armed with powerful new molecular-research technique, a few scientists began to ________ these genetic phenomena. They have discovered that a gene called Sir2—which is present in all animals, including humans —is ________ for the health benefits of calorie restriction perhaps by repairing our DNA. But if we had to restrict our calorie intake ________ 30 to 40 percent would it be of any practical use? Few of us would be capable of restricting our diets so severely that we were constantly ________. Whether or not it made life longer, it would surely make life ________ longer.

【推荐3】Two new studies add further pieces to the jigsaw puzzle that is human evolution. One reports a (n)_________extra member of the genus Homo. The other casts _________ on possible interbreeding between three human species in the Middle East.

Homo longi--- “Dragon man” into English from Chinese, via Latin---is not a (n)_________find, but a reinterpretation of an existing one. The cranium (头盖) in question was dug up in Harbin in1933 and is_________at Hebei GEO University, in Shijiazhuang. It is146,000 years old and was_________ badged as an archaic form of Homo sapiens (智人). But Ni Xijun and Ji Qiang, who work at the university, disagree. As they report in the Innovation, the cranium would indeed have contained a brain similar in size to a modern human’s, but the fossil is too large to be sapiens and has molars and eye sockets which dwarf those of people today. Dr Ni and Dr Ji also realised that it is too long and low to be sapiens. It lacks the_________of a modern human cranium.

This is good news for_________ of the recent- African- origin theory, which holds that most non-African human beings alive today are descendants of a small number of migrants who_________to Asia from the Horn of Africa about60, 000 years ago, meaning that any non- African human fossil from before that date is probably of another species descended from earlier, non- sapiens departures from Africa. The question was, which earlier species did the Harbin fossil represent? By_________it with known archaic humans, including Homo erectus, Homo floresiensis, Homo heidelbergensis and Homo neanderthalensis, Dr Ni and Dr Ji__________ that it was none of them, and must therefore be new to science and so worthy of its own name. There is, however, one other possibility-for there is a now-extinct type of human of which no cranium has yet been __________ . Homo denisova’s existence was established by the extraction of DNA from a finger bone, and traces of that DNA, a remnant of interspecies breeding，still exist in modern humans, notably in China. Since one of the Harbin fossil’s molars perfectly matches the size and root __________ of a molar from the Denisova cave in Russia, after which Homo denisova is named, it may be that Dr Ni and Dr Ji have actually identified the first Denisovan cranium.

The other study, published in Science by Israel Hershkovitz of Tel Aviv University, also speaks to the question of interspecific interbreeding. Even supporters of the recent-African-origin theory recognise that there was, __________, an earlier “ leakage” of Homo sapiens from north-east Africa into the Levant. Dr Hershkovitz and his colleagues have been examining fossils of __________ antiquity—120,000-l40,000 years-- collected from Nesher Ramla, a site in Israel. These, they found, have sapiens-like jaw bones, Neanderthal-like molars and crania similar to those of Homo erectus. This suggests to them that they are the __________ of miscegenation between all three.

【推荐2】With billions of stars in our galaxy (银河系), many circled by planets, the chances are there should be advanced life capable of reaching out to us. Yet after decades of looking and listening, we have found ___________.

This apparent conflict is known as Fermi’s paradox- Some have used it to argue that the search for extraterrestrial(外星球的)intelligence (SETI) is sure to ___________ .

But a mathematical analysis of SETI searches done so far claims that the usual explanation for the paradox— that there is nobody out there—is ___________. Instead, it suggests the best explanation is simply that we have barely scratched the surface in our ___________ for extraterrestrial intelligence.

Jason Wright at Pennsylvania State University and his colleagues analysed the many variables involved in SETI, which involves searching for radio signals from other ___________ . These include what to look for, where to look, how often and for how long. They then devised an equation that computes the ___________ of the galaxy checked so far. The team says that the volume of the galaxy that has been checked by SETI so far is roughly___________ to just a single bathtub of water in the world’s oceans.

“You don’t have to do a calculation to say we’ve only just ___________ ,” says Duncan Forgan at the University of St Andrews, UK, who is a member of the UK SETI research network. ”But they’ve done a nice job of showing the huge scale of the problem___________.“

As well as putting SETI in context, the equation can help researchers see which search techniques have been used less than others. ____________ , we only developed the technology to listen for higher radio frequencies quite recently. ”But we’re getting better at that, so that variable will now shrink,“ says Forgan.

However, advances in ____________ will only take us so far. Certain variables, such as how often a message from space might be repeated, cannot be____________. A signal sent once a year can only be listened out for once a year. ”There are things we can do better and things we can’t,” says Forgan. “We just have to ____________ and wait for the universe to do its thing.”

Forgan has a book coming out that discusses 66 potential ____________ for Fermi’s paradox. They include the possibility that Earth is somehow unusual in its ability to harbour intelligent life or that technological civilisations are rare. Or perhaps they are ____________ but short-lived. “Genetic or nuclear disasters might wipe you out,” says Forgan.