Assertion: viagra's sildenafil | /r/CapableOf | help to maintain erection
Facets:
value: by controlling the enzyme
type: MANNER
Source sentences:
text: By controlling the enzyme, sildenafil helps to maintain an erection after the penis is stroked.
text: By controlling the enzyme, sildenafil helps to maintain an erection after the penis is stroked.
text: By controlling the enzyme, sildenafil helps to maintain an erection after the penis is stroked.