Complex sentence: In the 1920s Germany produced about 15 million tons, but output plunged to 6 million in 1933 under the Nazis steel output peaked at 22,000,000 tons in 1940, then dip to 18 million in 1944 under Allied bombing.
Split into simpler sentences: In the 1920s Germany produced about 15 million tons, but output plunged to 6 million in 1933. Under the Nazis, steel output peaked at 22 million tons in 1940, then dipped to 18 million in 1944 under Allied bombing.