2 . Imagine how you’d feel if you had to get more than 9,000 tons of junk out to the sidewalk. That’s how much trash is floating around in space. In fact, there’s about 4 million pounds flying over our heads in low-Earth orbit. Daan, a Dutch artist, and his team at Space Waste Lab have come up with a creative plan that could clear up space junk in a spectacular fashion.

①Most space waste comes from dead satellites and rockets. Functioning satellites are the backbone of the information systems that keep our world running smoothly. But all the satellites eventually become obsolete within just a few decades. When they die out, there’s the problem of them drifting in outer space, collecting in what scientists call the “graveyard orbit.”

Maybe you’re thinking, “Why should I care about garbage 12,500 miles above me?” Well, all that fun stuff that satellites help beam down to us—mobile games, Instagram, cat videos—could be shut down by space waste. Lots of old junk floating around up there, plus new satellites added each year, means more and more high-speed collisions (碰撞). And when chunks of junk crash into one another, they break apart into millions of pieces, quickly building up speed and turning into fast-moving objects, which are dangerous to operational satellites as well as astronauts working on the International Space Station.

②Space waste is a problem that’s escalated so much, some scientists say that by 2050 we’ll be forced to stop launching new spacecraft altogether, including new satellites. Think about that for a minute. When the last satellites finally become disused, GPS, cell phones, and the Internet will no longer function.

③So we have to find a way to deal with this space garbage, and Daan pictures a sort of trash pickup, which involves groups of small spacecraft casting large nets into orbit that would collect space debris (碎片) and send it back toward Earth at top speed. Here’s the best part—while reentering Earth’s atmosphere, the pieces of junk would burn up all at once, creating a light show similar to hundreds of shooting stars falling in the night sky. A spectacle indeed!

To get ready for such an amazing effort, Space Waste Lab has been traveling to major cities across Europe and enlightening the public on the problem of the junk in space. ④But Daan doesn’t just talk about ways to relieve the problem—he’s created something a little grander than that. In October 2018, his team launched Space Waste Lab Performance, an outdoor art exhibition that shows the location of each piece of space trash using large lasers that make each debris look a bit like a star wandering slowly and silently over the sky, allowing viewers to wave and say, “Hallo, space trash!”

1. The word “obsolete” (paragraph 2) is closest in meaning to “______”.

A．accessible	B．profitable
C．floating	D．outdated

2. According to the passage, which sentence best replaces the question mark in the diagram?

A．Working satellites can be damaged and astronauts can be hurt.

B．Satellites can help people track the weather and find new locations.

C．There is more junk floating in space each year as new satellites are added.

D．The Space Waste Lab Performance can show people where satellites are located.

3. Which of the following best supports the idea that space waste should be dealt with very soon？

A．Sentences ①	B．Sentence ②
C．Sentence ③	D．Sentence ④

4. Which of the following might be the best title of the passage?

A．Space Junk Harms Digital Systems

B．Artists’ Proposal to Save Space

C．A New Glimpse into Outer Space

D．Test of Waste Collection Nets

3 . 阅读下面材料，在空白处填入适当的内容（1 个单词）或括号内单词的正确形式。

According to the “Big Bang” theory, after settling into a solid globe, the earth exploded so     1    (violence) that it was not clear     2    the shape would last.   Meanwhile, the explosion produced many gases, which were in time     3    (make) the earth's atmosphere. The continued presence of water appeared as the earth cooled   down, making possible the     4    (develop) of life on the earth. Many millions of   years later, with tiny plants     5    (multiply) on the surface of the water, green       plants began to grow on land,     6    (follow) by insects, amphibians, reptiles and     dinosaurs. After the age of the dinosaurs ended, all mankind, in     7    (it) turn,          became the   most   important   animals     8    the   planet. Unfortunately, however, human beings put too much carbon dioxide into the atmosphere. As       9    result,   the increasing heat from the sun was prevented from escaping into space. So whether life will continue on the earth     10    (remain) unknown.