1     (doubt), Earth is becoming warmer and there is strong evidence of     2     causes the dramatic change in the global climate. Actually, the “greenhouse effect” is     3     (blame). The rise in temperature has     4     (lead) to an increase in extreme weather and natural disasters worldwide, not only     5     (cause) serious damage, but also costing human lives. To reduce greenhouse gas emissions, governments need to consider making policies and     6     (take) appropriate actions and measures while we as individuals can also reduce our “carbon footprint” by restricting the amount of carbon dioxide our lifestyles produce.

China     7     (make) great progress in space programme in recent years, including Yang Liwei’s successfully orbiting Earth in the Shenzhou 5 spacecraft in 2003 and Chang’e 4’s exploring the surface of the far side of the moon to make     8     (measure) and observations.

The future of space exploration remains bright.     9     the difficulties, scientists hope future discoveries will not only enables us     10     (understand) how the universe began, but also help us survive well into the future.

Xi'an,or Chang'an as it was called for many centuries,has been a built-up urban area for over 3,000 years,and once     1    （serve）as capital for 13 dynasties.It is home     2     many immovable cultural heritages,three of     3     are on the UNESCO 's world cultural heritage list.

These days,the city has made     4    （effect）exploration in building modernity while preserving historical legacy（遗产）.A recent piece of news     5    （announce）by Shaanxi's cultural relic authority caused nationwide attention,that a ruin of ancient capital dating back to Qin Dynasty was unearthed during the construction of the Xi 'an MetroLine5.In order to protect the ruin,the metro line may have to change     6    （it）route.

    7     （face）the heavy and important task of protecting cultural relics while promoting urban construction,Xi’an made active    8    （attempt）.Rails of the metro system are built 15 to 20 meters underground in order to protect the ancient tombs which are     9     （usual）buried in the layer within5meters from the surface level.Besides,the metro constructors have also painted the walls inside the stations with historical stories,presenting       10     visual feast for citizens.

4 . Nobody wants to snack on plastic bags or soda rings, but according to a recent study from the University of Neweastle, we could be consuming roughly a credit card's worth of plastic every week.

Microplastic, which are less than a quarter-inch size and come in various shapes, have polluted the natural world and infiltrated(渗入)our bodies. The first clue to microplastic exposure in humans came around 2013, when scientists discovered plastic particles in seafood prepared for consumption. But in 2019, when the University of Newcastle study was published, the scientific community understood that the problem was considerably broader. Microplastics shed off clothes and tires and have been found in beer, honey, table salt and other food items. We breathe in plastic staying in the air and drink plastic floating in our drinks. It's no stretch to conclude that our exposure is significant. What we don't know is what this means for us.

The amount of evidence collected on this subject is growing rapidly, according to Scott Coffin, a toxicologist(毒理学家). Studies done on mice and rats have found that plastic in their bodies can severely damage cells and cause stress.

Because microplastics are too small to clean up, the only solution is to stop plastic waste at the source. And doing so would take a thorough adjustment, given that plastics are deeply embedded in our economy and lifestyle. Stopping using them would fundamentally affect countless industries, including textiles(纺织业), transportation and manufacturing.

"I think we need to have more studies coming out that are directly related to human health before we see a lot more concern from the general public," Scott said. "It takes a lot to convince people that something that is really convenient for them to use is something they should sacrifice."

The question of microplastics and human health needs more attention—from the scientific community ,the general public, the government and funding groups. The issue isn't being ignored, but it's not being prioritized either.

    1    (lie) under waters across the globe are an estimated three million shipwrecks, all of     2     indicate human attempts over the centuries to explore Earth's furthest corners. While there is little land on our planet left unexplored, the vast sea bed almost     3    (remain) unknown.

Considering our limited knowledge, it's not surprising that exploration of the oceans constantly brings about discoveries in various     4    (science) fields.

First, many archaeological finds are made in shallow waters, including whole cities     5    (bury) underwater. The ruins offer precious information about the past. However, the challenges of pressure, darkness and intense cold at vast depths make     6     difficult to discover more of the past.

Amazing biological discoveries are also being made, like the barreleye living 6,000 meters below the ocean's surface. Such discoveries enable us     7    (have) a better knowledge of the capacity for life even in extreme circumstances.

Additionally, so far more new natural resources such as fire ice     8    (find) in oceans. Besides, the research conducted by China's underwater vessels helps scientists identify areas for deep-sea drilling and better understand how the sea bed was formed.

Humankind is entering a new age of oceanic discovery. Oceans will be as familiar     9     us as the land where we live through all-round international     10    (cooperate).

7 . How can having a childlike view of the world help the environment? Danish eco-artist Thomas Dambo combines a talent for recycling with a fairy-tale imagination to bring people worldwide closer to nature.

For the “Guardians of the Seeds” exhibition, Danish eco-artist Thomas Dambo built five trolls from discarded wood materials, which were appointed by Coastal Maine Botanical Gardens (CMBG) for its splendid riverside woodland.

The exhibition composed of the five trolls aims to give visitors an emotional connection with nature that will encourage them to become keepers of it. For the exhibition, Thomas came up with a story that a family of trolls hid 10 golden seeds to protect the old forest. Using a map that's provided, visitors follow clues to find where the seeds are hidden.

Besides using carefully selected recycling materials to produce his works, to challenge himself creatively, the artist allowed for a degree of production on-site. He gave a skinny troll named Birk a beard made from the roots of fallen trees. The fur of another troll Roskva is made from bark. Also, Gro, sitting with her eyes closed in a yoga pose, has a tongue made out of a nearby deserted planter.

“Thomas wants people to interact with them,” says Gretchen, president of CMBG. “He wants it to be a journey of discovery where you're walking along and all of a sudden this big magical being appears in front of you. These are friendly, happy trolls. They're not scary, mean trolls.”

Thomas hopes that “Guardians of the Seeds” gives viewers the same joy he gets from an occupation that he compares to a hobby. He says too many people lose their playfulness in their adult life. The key quality of his work is just its playfulness. One of his trolls sits on a real car on a hillside, appearing to cheerfully ride it. He wants to reactivate a childlike imagination in adults so they begin to see trash as objects that can be repurposed in practical and even picturesque ways. And he loves to entertain kids, too.

Nowadays, Mr. Dambo gets a kick out of seeking waste everywhere, hoping to find more stuff he could refashion into something amazing.

9 . British sculptor Jason Taylor has made it his mission to use his talent to conserve our ecosystems by creating underwater museums. Over the years, the environmentalist has put over 850 massive artworks underwater worldwide. On February 1, 2021, Taylor launched his latest work---The Underwater Museum of Cannes.

“The main goal was to bring attention to the fact that our oceans need our help,” Taylor told Dezeen. “Ocean ecologies have been destroyed by human activity in the Mediterranean over the past few decades, and it is not obvious what is taking place when observing the sea from afar.”

The Underwater Museum of Cannes contains 6 sculptures featuring local residents of various ages. They range from Maurice, an 80-year-old fisherman, to Anouk, a 9-year-old student. Towering over 6-feet-tall and weighing 10 tons, the faces are sectioned into two parts, with the outer part like a mask. The mask indicates that the world’s oceans appear powerful and unbeatable from the surface but house an ecosystem that is extremely fragile to careless human activities.

Though the waters surrounding the sculptures now appear a pristine blue, the seabed was filled with old boat engines, pipes, and other human-made trash when the project began about four years ago. Besides removing the trash, Taylor also restored the area’s seagrass. Just one square meter of the seagrass can generate up to 10 liters of oxygen daily. The seagrass also helps prevent coastal erosion and provides habitats for many ocean creatures.

“The idea of creating an underwater museum was to draw more people underwater and develop a sense of care and protection,” Taylor told Dezeen. “If we threw unwanted waste near a forest, there would be a public outcry. But this is happening every day in our surrounding waters and it largely goes unnoticed.”

10 . Shining just 12 light-years from Earth, the star Tau Ceti so resembles the sun that it has appeared in numerous science- fiction stories and was the first star astronomers ever searched for signs of intelligent life, half a century ago. In 2012 Tau Ceti grew still more interesting when astronomers reported five possible planets somewhat larger than Earth circling closer to the star than Mars orbits (围绕……运动) the sun—one of which is in the star’s habitable zone. Newly released images taken by the Herschel Space Observatory provide even more insight about Tau Ceti’s solar system: greater detail about its dust belt.

Dust arises when asteroids and comets (小行星和彗星) crash into one another, so its location reveals where these dust- creating objects—which are too small to be seen directly—orbit a star. In Tau Ceti’s case, “it’s quite a wide dust belt,” says Samantha Lawler of the University of Victoria in British Columbia. As her team reported in November, the belt’s inner edge is roughly two to three astronomical units (AUs) from the star, which is the position of our own sun’s asteroid belt. (An AU is the distance from Earth to the sun.) Tau Ceti’s dust belt extends out to 55 AU, which would be just beyond our system’s main Edgeworth-Kuiper belt, the zone of small bodies whose largest member is probably Pluto. Presumably full of asteroids and comets, Tau Ceti’s dust belt most likely lacks a planet as large as Jupiter, Lawler says. The gravity of such a massive planet would have driven away most small space rocks.

Within a year a new series of radio telescopes in Chile called ALMA should provide a sharper view of the disk, especially of its inner edge. The ALMA images will help astronomers confirm whether the star’s five proposed planets are indeed real. If the disk overlaps the planets’ hypothesized (假设的) orbits, then they probably do not exist; they would have kept away most asteroids near the star, removing the source of dust.

If those planets do exist, however, Lawler’s team suggests that Tau Ceti’s planetary system may resemble what our solar system would have looked like had the four giant planets—Jupiter, Saturn, Uranus and Neptune- never formed: small planets orbiting close to the star, and nothing but asteroids, comets and dust beyond.