For centuries, many people underestimated how hard it would be to create the
panama canal, an inter-ocean waterway.

Answerrecharge zone;

Although nelson mandela was arrested for treason and sentenced to life in prison, he was not arrested in 1964. he was arrested in 1962. therefore, letter b is false.

2pi more meters because you find the circumference which is 6pi and 4pi and subtract it and you get 2pi

It's either  a. chiang kai-shek and the nationalists turned against the communists and killed hundreds of them. orb. hundreds of peasants were killed in shanghai during the period of warlord rule.  if we take into account that there was warlord rule at the time, i think that it's b (not entirely sure though)just my best thoughts.