With no explanation, label each line with "location-GPE", "O", "product-weapon", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
In
January
1969
,
U.S
.
armoured
cavalry
units
began
exchanging
their
M48A3
Patton
tanks
for
the
M551
Sheridan
Armoured
Airborne
Reconnaissance
Assault
Vehicles
;
by
1970
over
200
Sheridan
tanks
were
operating
in
Vietnam
.
In:O
January:O
1969:O
,:O
U.S:location-GPE
.:location-GPE
armoured:O
cavalry:O
units:O
began:O
exchanging:O
their:O
M48A3:product-weapon
Patton:product-weapon
tanks:O
for:O
the:O
M551:product-weapon
Sheridan:product-weapon
Armoured:product-weapon
Airborne:product-weapon
Reconnaissance:product-weapon
Assault:product-weapon
Vehicles:product-weapon
;:O
by:O
1970:O
over:O
200:O
Sheridan:product-weapon
tanks:O
were:O
operating:O
in:O
Vietnam:location-GPE
.:O