Answer:
often
Explanation:
it is seldom. As the opposite of the color white is to black.
"Vladimir Lenin<span> engineered the Bolshevik revolution in Russia in 1917 and later took over as the first leader of the newly formed </span><span>Union of Soviet Socialist Republics"</span>
a multilateral system of trading in which a country pays for its imports from one country by its exports to another.
JFK was much younger than any other candidate running for president. The election was also very close between JFK and Nixon.
This was the first presidential election ever held on television.
Also computers were recently introduced.
I have to say B. The rest were concepts made in Greece, by Greek philosophers, politicians, or mathematicians. An example for an advancement in math is the Pythagorean Theorem. I hope this helps!
