a) MTP refers to Medical termination of pregnancy which is the process which is used to terminate the pregnancy in case the pregnancy is risky for the life of mother or the child. The MTP ACT defines the safe period for termination of pregnancy as 20 weeks. Beyond this period, the termination can be dangerous for the life of the child and mother. b) The principles to prevent the sexually transmitted diseases are: Prevent unprotected sexual contact. Treatment of the people with sexually transmitted diseases.  Education and awareness about sex and these diseases. Use barrier methods for preventing transmission of diseases.