Will we know alien life when we see it?
1. part a: which statement best expresses the central idea of the text?

a
astrobiologists know that life exists on other planets, but they don’t think that we will ever be able to recognize or study it.
b
while astrobiologists suspect that there may be alien life on other planets, they believe it might exist or develop in a way that is unfamiliar to us.
c
in order to identify and study life on other planets, scientists must better understand the strange life hiding on our own planet first.
d
astrobiologists’ definition of living and nonliving things are too vague and need to be made more specific before they can identify living things on other planets.