The first step toward the reunification of germany took place in november 1989 when
a. all germany elections were held for a single german parliament
b. the berlin wall was opened and free entry to west berlin was allowed
c. a plebiscite was held for the german people to vote on unification
d. gorbachev mediated unification between leaders of the two germanys

isaac newton first proposed that earth was not perfectly round. instead, he suggested it was an oblate spheroid—a sphere that is squashed at its poles and swollen at the equator.

the idea of the earth being a flat disc is also inconsistent with the fact that a given lunar eclipse is only visible from half of the earth at a time. the only shape that casts a round shadow no matter which direction it is pointed is a sphere, and the ancient greeks deduced that this must mean the earth is spherical.

the answer would be logic.