Scientists know of more than 1,000 volcanoes on the surface of Venus, Earth’s “sister” planet. A big question has been: Are they still active? The scientists say yes.
Their evidence for recent volcanic activity on Venus comes from a lava (熔岩) flow in the planet’s northern hemisphere. The flow is hotter than the rocks around, which means the lava might still be cooling off. “The flow we studied seems to be very young---it is still warm inside,” Nataliya Bondarenko said.
Venus is a difficult planet to study from Earth because it is surrounded by thick clouds. Telescopes on Earth can’t see through these clouds, so the best information about Venus comes from spacecraft orbiting it.
Bondarenko and her colleagues studied the lava flow using data from NASA’s Magellan mission. That spacecraft spent four years in orbit around Venus and used radar to make a map of 98 percent of the planet’s surface. On October 11th, 1994, the mission ended, and the spacecraft plunged (跌落) through Venus’ heavy cloud cover and crashed onto the planet below.
While in orbit, the Magellan craft sent microwaves, which can go through Venus’ clouds, to the surface. Microwaves are invisible and can be as long as three feet. These waves are a kind of energy, like light. And like light, they bounce off surfaces. The way the waves bounced off the Venus’ surface and back to the craft supplied information that the scientists used to estimate the temperature of various parts of the planet’s surface. Bondarenko’s team found that the lava flow was hotter than its surroundings---which may mean the lava flow is in the process of cooling.
The scientists say the lava flow can’t be very old because if it were, it would have cooled off enough that Magellan wouldn’t have noticed the difference in microwaves. She adds that the flow appears in a 1978 view of the surface that a craft called the Pioneer Venus Orbiter captured.
1.What happened to Magellan in the end?
A. It was floating in space forever.
B. It flew into heavy clouds.
C. It returned to the Earth.
D. It fell onto Venus.
2.How could Bondarenko judge the temperature of the Venus?
A. By looking at it with a powerful telescope.
B. By measuring the thickness of clouds over Venus.
C. By calculating the microwave bouncing off Venus’s surface.
D. By orbiting Venus for 4 years in a spacecraft.
3.The best title for the passage may be “______ ”.
A. Warm lava on Venus
B. More volcanic eruptions on Venus
C. Venus is just like a big active volcano
D. Lava flows are first found on Venus
A South African farmer is receiving phone calls from his sheep after equipping them with cell phones to keep tabs on the flock amid recent livestock thefts, according to local press Wednesday.
When the sheep call, it is always bad news for farmer Erard Louw of the Cape Town suburbs, as the phones around their necks are only set to switch on when the sheep start running, a sign that thieves have cut through the fences.
"As they run it gives me a phone call and says 'Sheep One' or 'Sheep Two' and so on, so at least I know where to start looking because the farm is 750 hectares (1,850 acres)," Louw told the Cape Times daily.
Louw attached the phone-like security device to the collars of four sheep in separate flocks after thieves sneaked in and stole 27 sheep and 13 lambs a couple of weeks ago, driving Louw to rack his brains for ways to protect his animals.
He said there was no use calling nearby police, as they were stationed too far away and in his experience they either lacked an available car or the vehicle was out of fuel or missing tyres -- also the work of thieves.
According to Louw, the cell phones have already proved their worth, with one sheep-snatcher caught thanks to the device.
Still, with theft attempts currently at their peak, given long winter nights and early nightfall, a few sheep-robbers managed to get away in spite of the device.
"The phone did start ringing that night and I went out," he said, but added that he was too late.
1.Why did Erard Louw attach the phone-like device to the sheep he raises?
A. Because he thought it was fun to do.
B. Because the police there didn’t care about animals.
C. Because he liked hi-tech very much.
D. Because he wanted to protect them against thieves.
2.What does the underlined expression in Paragraph 4 probably mean?
A. Try very hard to remember or think of something.
B. Have a headache.
C. Make the brain bigger.
D. Shake the brain from side to side.
3.You can most probably read this passage______.
A. in a book
B. in a dictionary
C. in a newspaper
D. in a novel
It was a cold, wet day on June 6th, 2007, when 14-year-old Wasana arrived at school. Waiting outside his classroom for his classmates to ,Wasana stared at the ,then his eyes fell upon the 18-metre-high hill that at the back of the classroom.
He large amounts of rainwater flowing down the hill, and water was also bubbling at the base of a rock on the hill. For a few minutes, Wasana the water, wondering why it looked so . Then it hit him—the was similar to the video he was shown during Disaster Management classes. Fearing a disaster, he shouted at the students waiting outside their classrooms. “Run, run, don’t stay here! The on the hill is going to fall on us! ”
Chaos broke out as the ran to the open area that had been appointed as an emergency gathering point. When some teachers Wasana, he showed them the water gushing from the hill, and they started leading the students to safer ground.
Just then Principal Gurusinghe drove into the school. Wasana ran over to tell him what was happening. After the site, Grrusinghe knew the school was in The enormous rock at the top of the hill could come crashing down .
a group of teachers and older students Gurusinghe climbed the hill and tried to make the water flow away from the rock. They were too : ten minutes later, they heard screams as the huge rock rushed down the hill. There was little Grrusinghe and his group could do as they watched the earth their classrooms. Thanks to Wasana’s action and careful observation, was hurt in the accident.
1.A. rest B. dine C. chat D. arrive
2.A. rain B. hill C. book D. sun
3.A. stood B. placed C. faced D. hid
4.A. felt B. knew C. heard D. noticed
5.A. glared at B. stared at C. shouted at D. aimed at
6.A. dangerous B. moving C. interesting D. familiar
7.A. show B. view C. scene D. scenery
8.A. heading B. leaving C. going D. coming
9.A. angrily B. rudely C. happily D. wildly
10.A. rock B. water C. sand D. tree
11.A. villagers B. students C. principals D. climbers
12.A. blamed B. questioned C. approached D. instructed
13.A. choosing B. visiting C. examining D. clearing
14.A. relief B. loss C. security D. danger
15.A. at any minute B. for the moment C. for once D. at one time
16.A. Leading B. Demanding C. Covering D. Helping
17.A. nervous B. strange C. unique D. late
18.A. swallow B. threaten C. affect D. blow
19.A. legal B. quick C. direct D. united
20.A. no one B. only one C. anyone D. someone
If you often______ yourself, or in other words, ______ your strengths, you are likely to have______ self-esteem.
A. belittle; overlook; low B. belittle; emphasize; high
C. compliment; overlook; high D. compliment; emphasize; low
The police are ______ to become ______ people’s family problems.
A. reluctant; involved in B. innovative; reduced to
C. supportive; equipped with D. uncritical; ducked into
I’m definitely going to settle in the countryside when I retire. All the words have a similar meaning with the underlined word, Except ______.
A. surely B. actually C. certainly D. absolutely