Synthetic fuel Ruhr Area. In 1937, the four central Germany lignite coal plants at Böhlen, Leuna, Magdeburg/Rothensee, and Zeitz, along with the Ruhr Area bituminous coal plant at Scholven/Buer, had produced of fuel. Four new hydrogenation plants () were subsequently erected at Bottrop-Welheim (which used "Bituminous coal tar pitch"), Gelsenkirchen (Nordstern), Pölitz, and, at 200,000 tons/yr Wesseling. Nordstern and Pölitz/Stettin used bituminous coal, as did the new Blechhammer plants. Heydebreck synthesized food oil, which was tested on concentration camp prisoners. The Geilenberg Special Staff was using 350,000 mostly foreign forced laborers to reconstruct the bombed synthetic oil plants, and, in an emergency
Interlanguage fossilization opinion. The term, borrowed from the field of paleontology, conjures up an image of dinosaurs being enclosed in residue and becoming a set of hardened remains encased in sediment. The metaphor, as used in SLA literature, is appropriate because it refers to earlier language forms that become encased in a learner's interlanguage and that, theoretically, cannot be changed by special attention or practice of the target language. Despite debate over the degree of permanence, fossilization is generally accepted as a fact of life in the process of SLA. Many researchers have attempted to explain this. Workers have attempted to discover: