As for the first part, Cost, Radiation exposure to humans, No water or heat, and unfit soil. As for the second, Astronomers, Botanists, and obviously your fair share of rocket scientists and math matitions for the way up.
punctuation, Nobody can puncate with their voice.
Answer:
not sure
Explanation:
you would have to show the story
The sentence should be "I had joined the soccer team to meet new friends" if you're looking for a past perfect tense verb, since this is indication it is something that is not repeated.