Why didn't the League of Nations aid Ethiopia in their fight against Italian imperialism?

Which of these events was a severe setback for the u.s. war effort in the pacific?

How are the republican and democratic presidential candidates chosen? a. they are nominated by their state governments. b. each is nominated by his or her respective party. c. each is chosen by the governor of his or her home state. d. they are chosen by the house of representatives.

Which of the following is/are a major technological advances of the mayan civilization? a. the calendar c. math b. architecture d. all of the above