Explanation:
1 Formal demography limits its object of study to the measurement of population processes,
2 it refers to events as birth, death, migration, marriage and divorce
3 it studies only numerical data and human population
4 Formal demography is older approach to study population
1 Social demography deals with questions of population composition and change and how they interact with sociological variables at the individual and contextual levels
2 Social demography is analytical, statistical and quantitative study of human population
3 It studies both numerical data and social traits of human population.
4 social demography is newer approach to study population
A chronic illness and a communicable disease
<span>There is not such thing as a universally accepted standard of flexibility because there's no material that is taken as a reference point. You can't say it's twice the flexibilty of rubber or twice the flexibilty of bamboo or anything similar because no official reference points have been established in the SI system.</span>