What was the average life expectancy in the united states in the year 1900?
a. 40 years
b. 50 years
c. 60 years
d. 65 years

answer; the period of time known as the middle ages;

the triple alliance. germany and austria-hungary were already allies by 1879 when, worried about a threat from russia, they formed the dual alliance. italy joined the group in 1882. there was a concern about a possible attack from france and the alliance needed powerful friends to defend it.