a) Space exploration provides literally a university of opportunities for scientific and medical advancement. b) The exploration of the depths of space, other stars, and even other planets could help solve century-old questions involving where we came from, and how we got here. c) The study of alien environments could lead to the discovery of microbes, bacteria, and other prokaryotes which could lead to exponential leaps in the fields of evolution, and even medical treatment. d) The effect of zero-gravity on the human body could be examined, and possibly used to cure diseases. e) Even if the majority of missions were focused within the solar system, these would be the first stepping stones to moving beyond, and to exploring neighboring star systems, and eventually, the deepest reaches of space.
Which sentence (s) offer(s) expansion or explanation?
A、a
B、b
C、c
D、d
E、e