Assertion: acid rain | /r/CapableOf | become in early 1980s
Facets:
Source sentences:
text: As it pertains to the prepainted metal market, and especially to metal roofing, acid rain became an accepted and understood phenomenon in the late 1970s and early 1980s.
text: In the early 1980s, acid rain caused by NO2 and SO2 emissions from industry became a major environmental concern.