4 billion years ago the temperature was much higher due to repeated volcanoes and hot gases present in the atmosphere. There weren't any live forms on earth. ... The atmosphere had a different concentration of gases on the earth. There were no life sustaining gases.
Answer:
<u>B. Lithium, because it has two energy levels with one electron in the second level.</u>
Darwin's theory of evolution by natural selection can explain how antibiotics are becoming defective because the bacteria that is trying to be fought off might have had a mutation making it more likely to survive. Once that surviving bacteria makes offspring most of the first generation will die from the antibiotic but soon all of their offspring will produce a resistance to that antibiotic.
The answer is cor-rectally FOSSIL FUELS
i hope that this helps