Answer:
C. You cross from the western to eastern hemisphere
Explanation:
I believe this is the most reasonable answer but the question is a little confusing. If it is asking how to travel through different ecosystems then C is the most reasonable as A would only change the temperature and sometimes change the weather. B would keep you underwater all the time and you can't really switch ecosystems unless you got out. D, your staying in one ecosystem when climbing a mountain.
Hope this helps :)
Answer:
"The smallpox vaccine does not contain smallpox virus and cannot spread or cause smallpox. However, the vaccine does contain another virus called vaccinia which is live in the vaccine. Because the virus is alive, it can spread to other parts of the body or to other people from the vaccine site."
[Copy and pasted from a medical website]
Answer:
The natural selection on polygenic traits affects selection.
Explanation:
The natural selection process allows changes in frequencies of alleles in a character that is determined by single gene. The polygenic characteristics are disproportionately affected by natural selection as natural selection affect the phenotype distribution.
This occurs in three ways that are disruptive selection, stabilizing and directional selection.
Limestone is essential for the formation of petroleum reservoirs
Limestone is great for soil as due to its structure, it can buffer acidic chemicals in soil
It is useful in the prevention of explosions from mining that are caused from too much methane release
It is useful in mediating the effects of erosion the the environment