In the U$.$S$.,$ life expectancy rates in recent decades have $\_\_\_\_.$

Question $4$Answer

a$.$

continued to gradually rise

b$.$

gone up and down due to global issues such as military conflicts

c$.$

lowered as healthcare improves

d$.$

stayed the same since the mid$-1960$sIn the U$.$S$.,$ life expectancy rates in recent decades have $\_\_\_\_.$

Question $4$Answer

a$.$

continued to gradually rise

b$.$

gone up and down due to global issues such as military conflicts

c$.$

lowered as healthcare improves

d$.$

stayed the same since the mid$-1960$s