Sentence:In the 1940s and 50s the empty canal was used by a chemical and plastics company to dump nearly 20,000 tons (c.18,000 metric tons) of toxic waste; the [e1]waste[/e1] was sealed in [e2]metal drums[/e2] in a manner that has since been declared illegal.
 e1: waste. 
 e2 : metal drums.
Answer: Content-Container(e1,e2)