Original sentence: Davidson taught that "everything had to be questioned and explained".Doctors he has been a teacher to include John George Macleod, Professor Ronald Haxton Girdwood who discovered the link between folate deficiency and Megaloblastic anemia, Sir John McMichael, a  pioneer in the field of Cardiology whose works formed the basis of the treatment of cardiac diseases in Britain, and Harold Thomas Swan, who discovered and published two case-notes recording the successful clinical use of penicillin in 1930
Edited sentence: Davidson is remembered as a gifted teacher at the bedside, where he taught that "everything had to be questioned and explained".He has been a teacher to many well known doctors including John George Macleod, Professor Ronald Haxton Girdwood who discovered the link between folate deficiency and Megaloblastic anemia, Sir John McMichael, a  pioneer in the field of Cardiology whose works formed the basis of success in the treatment of cardiac diseases in Britain, and Harold Thomas Swan, who discovered and published two important case-notes recording the successful clinical use of penicillin in 1930