The answer here is D, and it's kind of obvious. But you probably already knew the answer and are just doing this for piece of mind.
Explanation: Just the fact that we don't know whether or not there even is extraterrestrial life rules out every other answer, without even needing to go in depth.
(Okay, I read your question completely wrong, it's asking for which one of these has been solved isn't it?)
This is tough because all of these other than D have been figured out. Go with the methane atmosphere then.
Answer:
The composition of the stars
Explanation:
All four options:
black fur, black eyes
black fur, red eyes
white fur, black eyes
white fur, red eyes
Are correct! (Select all four)
The hips ball and socket joint is much larger than the shoulders. its also protected by more muscle.
Explanation:
The giant-impact hypothesis is currently the favored scientific hypothesis for the formation of the Moon. Supporting evidence includes: Earth's spin and the Moon's orbit have similar orientations. Moon samples indicate that the Moon's surface was once molten.
