Cancer is a disease that usually results when a. a person has limited exposure to sunlight. b. mutations cause a person's body cells to divide uncontrollably. c. a person has a severe allergic reaction. d. a bacterium enters the body through a person's skin.

B. Mutations cause a person's body cells to divide uncontrollably. There isn't a signal for cells to stop dividing, so this can cause cancer because cancer cells won't stop dividing without this signal. 

The soviet union beat the us to the first successful launch, with the october 4, 1957, orbiting of sputnik 1, and later beat the us to have the first human in earth orbit, yuri gagarin, on april 12, 1961. the "race" peaked with the july 20, 1969, us landing of the first humans on the moon with apollo 11