WASHINGTON(AP)－Astronomers believe they’ve found the oldest thing they’ve ever seen in the universe：It’s a galaxy(星系)far, far away from a time long, long ago．
Hidden in a Hubble Space Telescope photo released earlier this year is a small point of light that European astronomers now calculate is a galaxy from 13．1 billion years ago．That’s a time when the universe was very young, just about 600 million years old．That would make it the earliest and most distant galaxy seen so far．
By now the galaxy is so ancient it probably doesn’t exist in its earlier form and has already changed into bigger neighbors, said Matthew Lehnert of the Paris Observatory, lead author of the study published online Wednesday in the journal Nature．
“We are looking at the universe when it was a 20th of its current age,” said California Institute of Technology astronomy professor Richard Ellis, who wasn’t part of the discovery team．“In human terms, we’re looking at a 4-year-old boy in the lifetime of an adult．”
While Ellis finds the basis for the study “pretty good”, there have been other claims about the age of distant space objects that have not held up to careful examination．And some experts have questions about this one．But even the doubters praised the study as important and interesting．
The European astronomers calculated the age after 16 hours of observations from a telescope in Chile that looked at light signatures of cooling hydrogen gas．
Earlier this year, astronomers had made a general estimate of 600 to 800 million years after the Big Bang(宇宙大爆炸)for the most distant unclear points of light in the Hubble photograph, which was presented at an astronomy meeting back in January．
In the new study, researchers focused on a single galaxy in their analysis of hydrogen’s light signature, further finding out the age．Garth Illingworth of the University of California, Santa Cruz, who was the scientist behind the Hubble image, said it provided confirmation for the age using a different method, something he called amazing “for such faint objects”．
(1)
We can learn from the passage that _________．
[ ]
A．
the universe came into being about 14 billion years ago
B．
the galaxy is believed to be the same as it was just born
C．
the newly-discovered galaxy is the oldest one in the universe
D．
the galaxy had traveled about 600 millions before the scientists found it
(2)
We can infer from the fourth paragraph that _________．
[ ]
A．
the universe is actually very young
B．
the life-time of the universe is surprisingly long
C．
the humans have been so able as to see far into the universe
D．
what we can see about the universe now is just the tip of the iceberg
(3)
What did some people doubt according to the fifth paragraph?
Probably you have seen photographs of the Grand Canyon(峡谷)，the great valley in the desert country of Arizona．But you must go there yourself to feel its true size and beauty．The Grand Canyon is one of the greatest natural wonders of the world．
The Colorado River formed the Grand Canyon over millions of years．Slowly, the river cut down through hard rock．At the same time, the land was rising．Today, the canyon is one and a half kilometres deep and 445 kilometres long．The oldest rocks at the bottom of the canyon are more than 1 billion years old．The width varies from about 200 metres to 29 kilometres across．The rim(边缘)or top of the canyon is about 2,300 metres above sea level on the South Rim, and about 3,000 metres on the other side, the North Rim．As a result, there are different kinds of plants and animals on opposite sides of the canyon．The South Rim is dry desert country．The North Rim has tall forests．
The canyon looks different at different times of day, and in different seasons and weather．At sunrise and sunset the red, gold, brown, and orange colours of the rocks are especially clear and bright．In winter, the canyon is partly covered with snow．
The view from the South Rim of the Grand Canyon is the best, Most visitors come to the South Rim and stay in campgrounds or hotels．Every point along the canyon's edge offers a different view．
The North Rim of the Canyon is quieter．It takes all day to drive there from the South Rim because there is only one bridge across the Colorado River．On the way, you go through Navado Indian lands, and a colourful pink desert called“The Painted Desert”．
You can walk down into the Grand Canyon, or you can go down on the back of a mule(小型电动机车)．You can also take a boat trip down the Colorado River, and camp on the beaches at night．But whether you see the Grand Canyon from the top or the bottom, it will be an experience that you will never forget．
(1)
The sea level on both sides of the Grand Canyon is ________．
[ ]
A．
the same
B．
changing with time
C．
various
D．
very low
(2)
From the passage we can know that the ________ of the canyon is different at different time．
[ ]
A．
length
B．
scene
C．
width
D．
height
(3)
If you go to visit the canyon you'd better go to ________．
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