The phrase "are underlined by a" is correct and usable in written English.
It can be used when describing something that is emphasized or highlighted by a particular element or factor.
Example: "The key themes of the essay are underlined by a series of compelling examples that illustrate the main arguments."
Alternatives: "are emphasized by a" or "are highlighted by a".
The parallels with Kubrick's film are underlined by a soundtrack of classical music by Elgar and Purcell.
These similarities are underlined by a double arrow in the heatmaps and framed in the dendrograms.
The valued partnerships that UNICEF has with businesses and organisations are underlined by a shared commitment to achieving change for children.
The associated risks are underlined by a well-documented case report concerning an individual who was planning to swim at a lake in Saskatchewan, Canada that was affected by a cyanobacteria bloom.
Despite progress, the need for the existing and continuing efforts to increase health research capacity are underlined by a recent assessment of publications involving health policy and systems research from the 71 LMICs that had worked with WHO to produce Country Cooperation Strategies.
The vintage vibe was underlined by a preoccupation with space.
The dire state of affairs was underlined by a second report last week from the International Federation of Red Cross and Red Crescent Societies.
The educative role of military service was underlined by a marked improvement of military schools.
The euro's fragility is underlined by a new study by Michael Bordo of Rutgers University and Harold James of Princeton University.
This was underlined by a startling piece of polling that helped kick-start Mr Cameron's makeover of the party.
SHANGHAI, Sept. 30 (AP) — Germany defended its Women's World Cup title with a 2-0 victoverover Brazil on Sunday that was underlined by a flawless, unyielding defense.
