Why should we explore space？Perhaps the best answer lies in our history.What made our ancestors move from the trees onto the plains？（1）

E

E

In exploring，the surrounding areas may be identified and prepared for.Without knowledge，these dangers have the ability to harm us.
   While many resources are spent on what seems a small return，the exploration of space allows new resources to be created.（2）

C

C

Knowledge or techniques acquired in exploring or preparing to explore always filter （慢慢傳開） from the developers to the general population.Techniques may be medical applications，such as new drugs or ways of living to increase the quantity or the quality of time lived.
   By studying alien worlds，we can place our own world in content.While space may hold many wonders and explanations of how the universe was formed or how it works，it also holds dangers.The chance of a large asteroid （小行星） hitting the Earth is small.（3）

A

A

   Some explanations for extinctions and evolution include strikes by asteroids.Our technology is reaching the point where we can detect such a threat and might be able to do something about it.
（4）

G

G

Without the ability to reach out across space，the chance to save ourselves might not exist.Earth is the only planet known to maintain life，but our ability to adapt could eventually allow us to inhabit other planets and moons.
   Our lifestyles would be different，but human life and cultures have adapted in the past and surely could in the future.（5）

B

B

A.But given time，it will happen.
B.Space allows us to expand and succeed.
C.Resources translate into success at survival.
D.With knowledge，their consequences may be reduced.
E.Nearly all successful civilizations have been willing to explore.
F.Scientists can function at world-class level in their specialist fields.
G.The dangers exist and knowledge can allow us as a species to survive.