Assertion: mustard gas | /r/CapableOf | make its debut
Facets:
value: on july
type: TEMPORAL
Source sentences:
text: Mustard gas made its debut on July 12, 1917 when German units near the Ypres salient lobbed 50,000 shells laden with the agent into British lines.
text: Chlorine, xylyl bromide and mustard gas all made their debut in the battlefields of World War I.