Complex sentence: At peace talks to the C Mandates of the League of Nations, Haber was appointed as the second member of the German delegation in May 1919, but resigned due to the hopelessness of his work in negotiations and took over the Coal Management Institute in Mecklenburg.
Split into simpler sentences: At peace talks to the C Mandates of the League of Nations, Haber was appointed as the second member of the German delegation in May 1919. He later resigned due to the hopelessness of his work in negotiations and took over the Coal Management Institute in Mecklenburg.