How to understand the high and low beam questions in Subject 4?

[RubyLee]

If the road is poorly lit at night but there are streetlights or other light sources, do not use high beams; use low beams first. When there are no surrounding lights and visibility is poor in the distance, promptly switch to high beams. When driving on roads with poor lighting conditions and frequent oncoming traffic, you can alternately flash high and low beams to avoid affecting other drivers.