Atoms with a(n) covalent bond share electrons.
That would be coal because you can cook with coal, build things out of coal, and use it for energy
the answer is C. systole of the left ventricle :))
The correct answer is option Selective breeding.
The selective breeding is a technique, in which two different individuals having a specific desired phenotype is present. Both the individuals have different desired phenotype. They are crossed together, so that a progeny having both type of phenotype or trait is obtained.
Hybridization, cloning and recombinant DNA technology emerged years after the introduction of selective breeding. These are very new tools used in DNA technology, whereas, selective breeding was from ancient times.