Original sentence: In 1980, 235 students began his teacher-training course at Hampshire College in Amherst, Massachusetts, but he was not able to continue with them through the end due to illness in 1981.Over the course of four summers from 1975-1978, he trained 65 teachers including Anat Baniel, Thomas Hanna and Linda Tellington-Jones in San Francisco at Lone Mountain College under the auspices of the Humanistic Psychology Institute
Edited sentence: In 1980, 235 students began his teacher-training course at Hampshire College in Amherst, Massachusetts, but unfortunately, he was not able to continue with them through the end due to illness in 1981.Over the course of four summers from 1975-1978, he trained 65 teachers including Anat Baniel, Thomas Hanna and Linda Tellington-Jones in San Francisco.at Lone Mountain College under the auspices of the Humanistic Psychology Institute