What is the MOST likely reason the author included the information about Clarence Crane and the pill-making machine?

Which of the following statements best describes the spread of communism in the years immediately following world war ii? a. the number of communist countries increased during these years. b. the number of communist countries decreased during these years. c. the number of communist countries stayed the same during these years. d. the number of communist countries increased in asia but decreased in europe. ( answer in the format above for me to understand)

Marine exptoration of oil uses seismic waves to locate oil in the seabed. what is a negative impact from seismic waves on the aquatic ecosystem of the ocean? a. seismic waves kill microoganisms b. seismic waves disrupts the sand and causes seafloor erosion c. seismic waves have virtually no adverse affects on marine life d. seismic waves damage the sonar that dolphins and whales use to orient themselves underwater

Me i really need which of these was an accomplishment of the han dynasty? the invention of the seismograph finding a water passage to europe the invention of the ballpoint pen the invention of the abacus