× Didn't find what you were looking for? Ask a question
Top Posters
Since Sunday
6
s
3
3
d
3
s
2
c
2
G
2
y
2
t
2
2
k
2
j
2
New Topic  
killian killian
wrote...
Silver Member
Posts: 6024
10 years ago
From where did the oxygen in the earth's atmosphere originate?
A) photosynthesis from plant life and single-celled organisms
B) chemical reactions between gas in the upper atmosphere and the solar wind
C) outgassing from volcanoes
D) atmospheric bombardment
E) oxidation of surface rocks
Read 504 times
2 Replies
Smiling Face with Open Mouth

Related Topics

Replies
wrote...
10 years ago
Now, I could be wrong but I am sure it is A
killian Author
wrote...
Silver Member
10 years ago
Thanks sir
Smiling Face with Open Mouth
New Topic      
Explore
Post your homework questions and get free online help from our incredible volunteers
  1020 People Browsing
Related Images
  
 2911
  
 809
  
 217
Your Opinion
Which industry do you think artificial intelligence (AI) will impact the most?
Votes: 405