Original sentence: After a year into his Wing Chun training, some of Yip Man's other students refused to train with Lee due to his ancestry ( his mother was of a quater German ancestry ) as Chinese were secretive in relation to teaching martial arts techniques especially to foreigners
Edited sentence: After a year into his Wing Chun training, some of Yip Man's other students refused to train with Lee due to his ancestry ( his mother was of a quarter German ancestry ) as Chinese were secretive in relation to teaching martial arts techniques especially to foreigners