Answer:
D
Explanation:
Sexual reprduction is when a sperm cell fertilzes an egg cell.
The answer is D. You really have to think about this one :)) I hope you get it right
O2 (oxygen) is a covalent compound
Nearly all life on Earth ultimately gets its energy from the sun, which gets "its"energy through nuclear fusion. <span>With the exception of hydrogen, all of the chemical elements needed for life were produced by nuclear fusion of lighter elements, either in the cores of stars or in the shock waves of supernova explosions.</span>
