Scientists suggest that two energy sources, __________ and __________, broke the bonds in the gases in Earth's primitive atmosphere, releasing atoms to form __________.

Question

Help! I forgot my book at school! Please!

Answer 1

http://www.google.com/search?hl=en&rls=com.microsoft:en-us:IE-SearchBox&rlz=1I7SUNA&pwst=1&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=two+energy+sources+broke+bond%27s+gases+earth%27s+atmosphere&spell=1

There may be an article in here that could help.