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: Creo que es B
Explanation:
P.S(eso fue muy difícil. Lo siento mucho si se equivoca.)
Answer:
In trees, most savanna adaptations are to drought--long tap roots to reach the deep water table, thick bark for resistance to annual fires (thus palms are prominent in many areas), deciduousness to avoid moisture loss during the dry season, and use of the trunk as a water-storage organ (as in baobab).
By studing the dieses or problems with the patients
Answer:
They also have a specialized non-lignified tissue (the phloem) to conduct products of photosynthesis. Vascular plants include the clubmosses, horsetails, ferns, gymnosperms (including conifers) and angiosperms (flowering plants).
