When stars like our Sun die, they bloat to become red giants and then eject gigantic clouds of gas and dust into space. Increasingly, however, scientists found themselves at a profound loss to explain how exactly dying stars could blow away these clouds. Now astrophysicists propose that unexpected chemical reactions during the formation of stardust could help solve this mystery.
Stars smaller than the Sun and up to eight times as massive die by swelling up into red giants before shedding most of their mass to shrink into very compact, dying embers (灰烬) called white dwarfs. Two kinds of red giants exist-those with lots of carbon, and others richer in oxygen than in carbon. Carbon-rich stars release carbon particles during their death throes. Scientists proposed these pitch-black grains absorb rays from the dying star and get shot into space by starlight, a theory that fit both the observations and computer models.
Increasingly, however, researchers could not explai
A. explain-the possible way of death of our Sun.
B. show the two types of red giants.
C. discuss on the way of red giants to become white dwarfs.
D. explore the origin of life.
When stars like our Sun die, they bloat to become red giants and then eject gigantic clouds of gas and dust into space. Increasingly, however, scientists found themselves at a profound loss to explain how exactly dying stars could blow away these clouds. Now astrophysicists propose that unexpected chemical reactions during the formation of stardust could help solve this mystery.
Stars smaller than the Sun and up to eight times as massive die by swelling up into red giants before shedding most of their mass to shrink into very compact, dying embers (灰烬) called white dwarfs. Two kinds of red giants exist-those with lots of carbon, and others richer in oxygen than in carbon. Carbon-rich stars release carbon particles during their death throes. Scientists proposed these pitch-black grains absorb rays from the dying star and get shot into space by starlight, a theory that fit both the observations and computer models.
Increasingly, however, researchers could not explai
A. There are more than two types of red giants.
B. Carbon-rich star releases carbon when it dies.
C. Stardust mainly consists of carbon, iron and silicon.
D. Star reposes during the process of death.
M: I don’t like our son at all. I like our daughter very much.
W: He is handsome and he is so bright that he is the best one in his class. Why don’t you like him
M: Because he will not treat us well when we are too old to do anything.
W: How do you know that
M: I have learned that from what you and I did.
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