New scientific knowledge help the building of the Panama canal because there was a decrease of workers getting sick of malaria and yellow fever. It was Colonel Gorgas, the Chief Medical Officer, who have read about discoveries linking mosquitoes and malaria. Due to these readings, he succeed in eradicating the cause of the disease therefore a decrease in people getting sick.
Explanation:
The Romans actually used urine to brush their teeth. They did this because of the presence of ammonia in it.
<span>Nationalism in the Balkans and a system of military alliances is the best selection for the major cause of World War One. </span>
The answer is "D. They transported goods across desert regions."