Assertion: trombone's valve | /r/HasProperty | pushed
Facets:
Source sentences:
text: Trumpet is one of the smallest brass instruments and has valves that can be pushed to change the pitch.
text: In contrast to the system in use in tubas and euphoniums, the default 'side' of the horn is the longer F horn, with secondary lengths of tubing coming into play when the first, second or third valves are pressed; pressing the thumb valve takes these secondary valve slides and the extra length of main tubing out of play to produce a shorter B♭ horn.