Assertion: direct current | /r/HasProperty | difficult
Facets:
value: very
type: DEGREE
value: to step up the voltage
type: PURPOSE
Source sentences:
text: Direct current is not used for long-distance power transmission because it is difficult to step up the voltage to a level that is efficient for energy transfer and then to step the voltage back down again for safe domestic use.
text: DC is very difficult to transport from one place to another.