What are the trade-offs between the collegial and chief-of-staff models of presidential staff organization? Which model seems to have predominated with recent presidents?

The "dependency ratio" is a measure of

A. the proportion of non-working population to working population. B. the proportion of individuals on government welfare to those not on government welfare. C. the degree to which the country is dependent on foreign aid. D. a measure designed to indicate dependency on foreign imports versus exports.

The ____________ strategy was introduced in 1991 by the WHO to control tuberculosis

Fill in the blank with correct word