Okay, let us fill in the gap in the question before we delve right into the explanation. Note that the capitalized words are the missing words in the question.
"A culture can be described as having LOW POWER DISTANCE if supervisors work closely with subordinates, professors work closely with students, and elected officials work closely with constituents.''
So, whether we all like it or not some people are going to hold more power than us. Power can not be distributed equally. But the way we react or respond to the inequality in power depends on cultures. The reason behind this is that some culture will accept this unequal distribution of power without questioning while some will.
Low power distance is all about been able to Question those people in power while High Power Distance is the opposite of Low power distance.