9. Discus Epidemiological triad.
Ans: Agent, host and environment- these three epidemiological factors which are involved in disease occurrence are commonly referred to as the ‘epidemiological triad or ecological triad’
10. Define discuss agent. Mention its.
Ans: It may be define as a substance, living or non-living or a force tangible or intangible, the excessive 
presence or relative lack of which is the immediate cause of particular disease.

14. Define community medicine. What are its aims and objectives?
Ans: Community Medicine:  According to WHO’ (1972) Community Medicine is, “A system of  delivery of comprehensive health care to the individual or family at the level of the community by a health team in order to promote physical mental and social well-being ”
Aims and objective of community medicine
Tow types of aims and objectives are as below –
            (a) General objectives: To provide clinical skill knowledge attitude to the students concerning delivery of the comprehensive health care to the people form the available source.
            (b) Specific objective:
(i) To provide clinical skill to the students at all levels for deaconess, screening referral treatment and follow up.
            (ii) To provide knowledge of skill to the students in public health administration, including- planning, organizing, budgeting, supervision, recording, reporting and evolution.
            (iii) To provide skill to be able to do public health work, such as-
            (a) Epidemiology of disease.
            (b) Control of communicable disease.
            (c) Environment sanitation.
            (d) Biostatistics.