Complex sentence: To finance his studies, Borlaug put his education on hold periodically to earn some income, as he did in 1935 as a leader in the Civilian Conservation Corps, working with the unemployed on Federal projects.
Split into simpler sentences: To finance his studies, Borlaug had to put his education on hold periodically to take a job. One of these jobs, in 1935, was as a leader in the Civilian Conservation Corps, working with the unemployed on U.S. federal projects.