With no explanation, label each line with "O", "event-protest", "person-other", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
Having
become
a
Marxist
in
his
youth
,
Sheng
participated
in
the
anti-imperialist
May
Fourth
Movement
in
1919
.
Having:O
become:O
a:O
Marxist:O
in:O
his:O
youth:O
,:O
Sheng:person-other
participated:O
in:O
the:O
anti-imperialist:event-protest
May:event-protest
Fourth:event-protest
Movement:event-protest
in:O
1919:O
.:O