Humans can cause an ecosystem to collapse by: a. collecting and chemically altering industrial waste to detoxify it. b. reducing habitat fragmentation. c. hunting a keystone species to extinction. d. building shelter belts next to farm fields.

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.

thrombocytopenia, which is a deficiency in blood platelets, can cause bleeding and bruising in the dermis similar to senile purpura. other possible causes include: exposure to ultraviolet rays and aging skin are common causes of senile purpura. senile purpura may also be a sign of collagen loss in the skin and bones.

the answer is b. glad to .