5 billion years ago" " The team of researchers analyzed seven melted meteorites that crashed into Earth during billions of years in our solar system.”可知.研究者通过分析熔化的 陨石来进行研究。 故选B. 3.D 细节理解题 由"This led them to conclude that water was likely delivered to Earth ...
D.Earth's oceans formed from water vapor that was released during theradioactive decayof elements embedded in Earth's interior. E.Scientists once thought that heat from Earth's interior forced water vapor into the atmosphere where it condensed into liquid water that accumulated over time into the...
Sustaining a permanent environment in space requires things many of us take for granted here on Earth: fresh air, water, food, a comfortable (and habitable) climate — even waste removal and fire protection. First, let's talk air. We all need oxygen, so the ISS has several methods of pr...
根据文中“But for many years, salt’s most important job was to protect food.” 但多年来,盐最重要的工作是保护食物。可知,故答案为Salt’s most important job was to protect food.【小题6】细节理解题。根据文中“For centuries, salt was also hard to get because its usefulness made it ve...
great harm. First, the destruction of industrial equipment, a serious impact on product quality. Second, the chemical composition of the soil changes, fertility decreased, leading to crop reduction and serious pollution. Third, the city to increase domestic water and industrial water treatment costs...
But the dispute is still far from settled. For a while, studies of comets seemed to back up the idea that Earth’s water came from asteroids. The recent Rosetta spacecraft was the first to orbit a comet and then also the first to send a lander (called Philae) to the comet’s surface...
Water is so vital to our survival, but strangely enough, we don’t know the first thing about it—literally the first. Where does water, a giver and taker of life on planet Earth, come from? When I was in junior high school, my science teacher taught us about the water cycle—evapora...
Living things depend on water, but it breaks down DNA and other key molecules. So how did the earliest cells deal with the water paradox?
on impact it would shatter and melt or even vaporize. Besides releasing a great deal of heat, the explosion would immediately set free any water trapped in the rock. If Earth formed from colliding embryos, it formed not cold but hot, and, assuming there was water trapped in the rock, it...
One theory previously thought to be true was that oceans formed when volcanic activity released gases and water from the Earth's mantle during the planet's first 100 million years. But Dr Mark Kendrick from the ANU Research School of Earth Sciences on Tuesday said the new discovery throws that...