Washington：NASA has announced evidence that Jupiter's largest moon，Ganymede，has a saltwater ocean under its icy surface.The ocean seems to have more water than all the water on Earth's surface，according to new Hubble observation.
New Hubble observations of Ganymede's magnetic field strongly suggest that the moon，which is the largest in our whole solar system，is home to a subsurface ocean.
Scientists estimate the ocean is 95 kilometres thick，which is about 10 times deeper than Earth's oceans.But unlike our salty waters，Ganymede's ocean is buried under 150 kilometres of ice.
While scientists have speculated(推测)since 1970s about the presence of an ocean on Ganymede－the largest moon in our solar system－until now the only observational evidence came from a brief flyby by the Galileo spacecraft，which didn't observe the moon long enough to confirm a liquid ocean.
This discovery marks an important milestone，highlighting what only Hubble can accomplish.In its 25 years in orbit，Hubble has made many scientific discoveries in our own solar system.A deep ocean under the icy surface of Ganymede opens up further exciting possibliities for life beyond Earth.
Scientists_have_already_confirmed_the_existence_of_an_ocean_on_Europe，another moon orbiting Jupiter，and NASA has announced plans to send an unmanned mission there searching for the life that might come with liquid water.
Hubble is a telescope that orbits Earth，but because of its impressive gravitational analyses it can be used to study the inside of far distant planets.Using these same principles，scientists could theoretically detect oceans on distant planets as well.
【语篇解读】 这是一篇关于天文知识的新闻报道。科学家们通过Hubble望远镜判断在木星上发现海洋的存在，人们期待更多的地球以外的生命存在。
1．What can we learn about the Ganymede from the passage?
A．It is a planet with the largest moon in our whole solar system.
B．Its ocean adds to people's excitement about life beyond Earth.
C．It will be used by NASA as a base for the Hubble telescope.
D．Its liquid ocean was first proved by the Galileo spacecraft.
【答案】 B 细节理解题。根据通过第五段中“A deep ocean under the icy surface of Ganymede opens up further exciting possibilities for life beyond Earth.”可知海洋增加了人们关于地球以外的生命的兴奋。故选B。
2．Which of the following best describes the writer's attitude towards Hubble?
A．Cautious. B．Doubtful.
C．Negative. D．Favourable.
【答案】 D 推理判断题。Cautious谨慎的；Doubtful怀疑的；Negative否定的；Favourable支持的。根据通过第五段中“This discovery marks an important milestone，highlighting what only Hubble can accomplished.”可知作者对Hubble的态度是支持的。故选D。
3．What does the underlined part in Paragraph 6 mean?
A．An underground ocean has been found in Europe.
B．The presence of an underground ocean in Europe is not possible.
C．It is now certain that there is an ocean on Europe.
D．No evidence has shown the existence of an ocean on Europe.
【答案】 C 句意猜测题。通过横线句子中的“confirmed the existence”和“NASA has announced plans to send an unmanned mission there searching for the life that might come with liquid water.”可知欧洲上空可能有海洋是确定的。故选C。
4．What type of writing does this passage belong to?
A．A term essay. B．A news report.
C．An experiment report. D．An exploration review.
【答案】 B 推理判断题。A term essay一个学期论文；A news report一个新闻报道；An experiment report一个实验报告；An exploration review一个探索评论。通过第一段“Washington：NASA has announced evidence...”格式及文章内容可知。故选B。
