Identify Which physical geographic factors challenged the builders of the Transcontinental Railroad? How did they adapt to
and modify the environment to overcome them?

b. africa to the americas

explanation:

richard milhous nixon (january 9, 1913 – april 22, 1994) was the 37th president of the united states, serving from 1969 to 1974, when he became the only president to resign (quit). he is also known for corruption and the watergate scandal which resulted in the public losing trust in him and his resignation.

answer: not really

explanation: the disadvantages of wikipedia are:

the advantages of wikipedia are