The second answer, It had been at Pearl Harbor, is correct.
Diseases introduced by the Columbian Exchange caused a sharp decline in population levels in the Americas beginning in the 15th century. The correct option among all the options given in the question is option "C". The natives never faced the diseases that attacked them and so they did not have any cure for them. <span />
The reason why Stalin pushed so hard for the US and Britain to open a second front against Germany was because Russia was bearing the burden of Germany's advance all by itself, and was suffering a great deal of losses in the process.
It might be said that the French explorers learnt how to make boats suitable for the coastal waters, rivers and lakes when they were at the great Lakes. They decided to build small sailing- ships to travel the entire length of the Missouri and the Mississippi River to New Orleans on the golf of Mexico. They built <span>native birch-bark canoes and large rafts.</span>
