13. a basic observation of a star is how bright it appears. this brightness is known as the star's a. absent magnitude. b. apparent magnitude. c. absolute magnitude. d. luminosity.

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.

the correct answer, according to e2020, is the second choice there is an occluded front in region a and a cold front in region b.