Which element must be present in an organic compound? (1) hydrogen (3) carbon(2) oxygen (4) nitrogen

the answer is 3) carbon

main component of organic compounds are the element carbon

C forms covalent compounds with other C atoms and form long chains resulting in forming compounds that are very useful to us in our day to day life

human body is made of 4 types of organic molecules.

C covalently bonds with other atoms such as H, O and N etc. forming a large array of useful compounds

shield volcanos are angry and get mad over the smallest things so much that there heads erupt   pahoehoe and a'a lava. a composite volcano is the poller opposite of a shield volcano. its   peaceful thing and knows how to control its emotions.      

0.88m hope i am correct : )