Assertion: engine's oil | /r/HasProperty | hard
Facets:
Source sentences:
text: Main disadvantage of molybdenum disulfide is anthracite black color, so oil treated with it is hard to distinguish from a soot filled engine oil with metal shavings from spun crankshaft bearing.
text: Main disadvantage of molybdenum disulfide is anthracite black color, so oil treated with it is hard to distinguish from a soot filled engine oil with metal shavings from spun crankshaft bearing.