Quasars are so distant that their light has taken billions of years to reach the earth;consequently,we see them as they were during the formation of the universe.
B)we see them as they had been during
C)we see them as if during
D)they appear to us as they did in
E)they appear to us as though in
during the formation of the universe怎么理解?为什么D不可以呢? |