What science fiction once told of other worlds far away, is now a fact. Astronomers prove

What science fiction once told of other worlds far away, is now a fact. Astronomers prove the existence of another solar system like ours with some planets in the constellation Andromeda(仙女座) .
Geoffrey Marcy is a professor of astronomy and physics at San Francisco State University and says, “What we have found now, for the first time ever, is indeed a fully-grown system of planets around the star Upsilon Andromeda, in which there are three planets, one close in, one at a middle distance, and one farther out.” The star is slightly larger than our sun. The planets are huge, like our Jupiter (木星)
Marcy’s partner in this research, Debra Fischer, describes the solar system, “Here’s the inner planet that goes around every 46 days, the middle planet that goes around every 242 days, and then the outer planet that goes around every three and a half to four years.”
Astronomically, it’s not far away, 44 light years. The sun of that solar system, Upsilon Andromeda, is so near and bright that it can be seen by using no equipment during summer and fall.
For twelve years astronomers searched the skies in the belief that if our sun has planets around it, surely others do, too. Geoffery Marcy says, “And then starting three and a half years ago, we began finding for the first time planets singly, one planet here around one star.”
“When I look up at the stars now at night, I can imagine easily that every one of them has planets around them,” says Debra Fischer.
It was the tremble in the star that led Marcy to discover the planets. “The star rocks around due to the gravity of the planet much like a dog owner gets pulled around by a little dog.”
Can they support life? We don’t know, because present technology is not advanced enough to determine what the planets are made of. That, Marcy says, is astronomy’s next challenge.
75. Which of the following can best show the relationship between Andromeda (A), Upsilon Andromeda system (U) and the three mentioned planets (P) ?
 
A                       B                     C                   D
76. What led to Marcy’s discovery of the planets?
A. That he found a dog owner was pulled by his dog.
B. The tremble of Upsilon Andromeda
C. That any planet has gravity
D. That he believes any star has its planets
77. We can infer from the text that scientists are     
A. to find out whether the planets can support life
B. to find means to municate with the living beings on the planets
C. to find means to travel to the planets
D. soon to be able to find another planet for life to live on 75--77 BBA