Which of the following is not true of viruses? a. they usually infect specific types of cells. b. they're nonliving particles. c. they reproduce on their own without hosts. d. they're able to crystallize.

economic impact of malaria is estimated to cost africa $12 billion every year. this figure factors in costs of health care, absenteeism, days lost in education, decreased productivity due to brain damage from cerebral malaria, and loss of investment and tourism.

a community that experiences major changes undergoes progress