The answer is Thomas Edison.
I believe b is the right answer however english is not my particular fortei
The Space Race. One of the most important forms of non-violent competition between the U.S. and the USSR during the Cold War was the Space Race, with the Soviets taking an early lead in 1957 with the launching of Sputnik, the first artificial satellite, followed by the first manned flight.
Harsh and extremely cold winter was the main geographical factor that added to German losses at Stalingrad.
Russia is well-known for its cold winters and many people from Western Europe even nowadays complain about severe weather conditions while visiting this country. Thus, this is not surprising, that cold weather became a serious obstacle on the way of Germans.
The County unit system. See the link below that will take you to that.
