c <- read.csv("C:/5772/country.csv", header = T)

head(c)

tail(c)

attach(c)

region

lifeExpFemale70plus <- subset(c, lifeexpf >= 70, select = c("lifeexpf", "region", "birthrate"))

?subset()

head(lifeExpFemale70plus)
tail(lifeExpFemale70plus)
tail(c)

c$birthCat <- NA

c$birthCat
c$birthCat[c$birthrate <= 31] <- 1
c$birthCat[c$birthrate > 31] <- 2

data.frame(c$birthrate, c$birthCat)