 Complete the following phrase:  During 193536, Welker worked for the as an expert on intelligence operations. Between April 1936 and May 1937 she was employed at a Moscow Orthopaedic clinic. Then, between 1937 and 1941 she worked as a language teacher with the , later becoming a teacher at a Moscow military academy, relocating with the academy to Stavropol when the Hitler-Stalin non-aggression pact 