Answer:
Carbon 3 is double bonded to an oxygen and attached to carbon 2 and carbon 4. :
Answer: Carbonyl group ( Ketone or aldehyde)
Carbon 17 is attached to an oxygen, which is attached to a hydrogen. :
Answer: Carboxyl group (Carboxylic acid)
A central carbon is attached to an amine, two hydrogens, and a carbon that is double bonded to an oxygen and single bonded to an oxygen attached to a hydrogen. :
Answer: Amide group
An amide group contains both amine and carboxyl

<span> the atmosphere holds about 21 per cent oxygen. Over the Earth’s 4.6 billion year history, oxygen did not appear in the atmosphere until perhaps about 2.5 billion years ago. Since then, oxygen levels have fluctuated in tandem with global geological and biological events, such as mass extinctions.</span>
They all just formed on top of each other like sedimentary rocks
Answer:People can drown or call or slip in
Explanation: