ANS: C
Oxygen in itself is a very reactive element. It binds quickly to other materials. Remember, free oxygen
only became abundant in our atmosphere when photosynthetic organisms began producing more.
Thus, if there is a large amount of free oxygen, then there is something present that is replacing it in
the atmosphere. This is likely to be a life-form of some sort. Information can be found in the section
Are There Other Ocean Worlds
ANS: C
A supernova is a shattering expansion in which there is an explosive release of energy. This explosion,
lasting only thirty seconds, can demolish a star. Information can be found in the section Stars and
Seas.
You might also like to view...
Which statement best represents the views of a mainstream economist from a technologically advanced country?
A. The Earth can support a world population of 30 billion people without serious environmental harm. B. The Earth can support a world population of 300 billion people without serious environmental harm. C. The Earth can support a world population of 30 billion people but with serious environmental harm. D. If the population of the earth exceeds 7 billion, we will experience a major human dieback.
Investments in Russia are most common in which of these products?
A) information technology B) oil and natural gas C) wind and solar energy D) wheat E) hydroelectric and forestry products
What is an isograd? What will be an ideal response?
What is the difference between a spring tide and a neap tide? Do spring tides only happen in the spring?
What will be an ideal response?