Cynthia Beall is going to do more research on ______.A．why Ethiopians have more haemoglobi

Cynthia Beall is going to do more research on ______.

A．why Ethiopians have more haemoglobin

B．why so many world-class endurance athletes are Ethiopians

C．whether the Ethiopians have different kind of haemoglobin

D．whether the Ethiopians have higher concentration of haemoglobin