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【单选题】Virtually everything astronomers known about objects outside the solar system is based on the detection of photons-quanta of electromagnetic radiation. Yet there is another form of radiation that perm...
A.
have been detected for 25 years.
B.
possess a variable electric charge.
C.
are usually extremely massive.
D.
record information about their own origin.
【单选题】Virtually everything astronomers known about objects outside the solar system is based on the detection of photons-quanta of electromagnetic radiation. Yet there is another form of radiation that perm...
A.
have been detected for 25 years.
B.
possess a variable electric charge.
C.
are usually extremely massive.
D.
record information about their own origin.