Arrange the events in the order in which they happened. most of earth’s surface was covered with ice and snow. hunter-gatherers began settling down in regions with abundant vegetation. wild fruits, vegetables, and grains began growing in fertile regions. earth began getting warmer. most humans gave up hunting and began practicing agriculture. ↓ ↓ ↓ ↓

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.

so, based on the research i've done. the u.s. government were always on a wild goose chase just to take down castro. he then retired his trone to his brother raul in 2008 due to some health issues. so it's obvious your answer would be:

castro had no allies from which he could receive aid.

hope this and have a fantastic day!

                                                    -wolfiewolffromsketch

either d or b, i'm not to sure. but my gut tells me it's prob going to be b