(A) They sprayed insecticides to kill mosquitoes and built lock systems to raise ships to higher elevation.
(B) ** They used pneumatic drills and dynamite to remove several of Panama’s mountains, making construction of the canal easier.
(C) They built new paved roads so that a greater number of dump trucks could remove the excavated earth.
(D) They used steam shovels to dredge the interior lake and bring its elevation down to sea level to build a sea-level canal.
EXPLANATIONS BELOW
Concept note-1: -“There is too much water, the rocks are exceedingly hard, the soil is very hilly and the climate is deadly. The country is literally poisoned, ” complained senior French engineer Adolphe Godin de Lépinay. Outbreaks of dysentery and epidemics of yellow fever and malaria decimated the workforce.
Concept note-2: -How did engineers overcome the obstacles that the geography of Panama prsed to the building of the Panama Canal? They sprayed insecticides to kill mosquitoes and built concrete locks to raise ships to a higher elevation.
Concept note-3: -To succeed in Panama, the builders scuppered the idea of digging a sea-level canal. Instead, they created a highly mechanized waterway that required locks three times longer than previously built. Suppressing mosquitoes made it possible for the American canal effort to succeed where the French had failed.
Concept note-4: -The building of the Panama Canal involved three main problems–engineering, sanitation, and organization.