In 1492 Christopher Columbus sailed to America with the Niña, Pinta, and the A. Cortés.
B. Isabella.
C. Santa María.
D. Tordesillas.

the causes of the dust bowls were severe droughts,   lands became dry and hard, temperature was higher than usual, hot and dry conditions killed crops, high winds. because of those factors, the winds kicked up dry soil and created clouds of dust.

written by alan ward and published in 2003. ward is a historian and was a professor at the university of connecticut.

if this isn't what you are looking i would like to know more details.