Assertion: class tram | /r/HasProperty | replaced by new z-class trams
Facets:
value: gradually
type: MANNER
value: in the 1970s
type: TEMPORAL
Source sentences:
text: The W-class trams were gradually replaced by the new Z-class trams in the 1970s, and by the A-class trams and the larger, articulated B-class trams in the 1980s.