Add spaces: Somepeoplethoughsucceededbeingasoloist,andamongtheirrepertoireitwasmostlytheconcertobyFerdinandDavidthatwasplayed,butalsootherpieces,likethetromboneconcertobyEugeneReiche(1878-1946)writtensomewhatliketheconcertobyDavid.PROMINENTTROMBONEPLAYERSOFTHE20.

Answer: Some people though succeeded being a soloist, and among their repertoire it was mostly the concerto by Ferdinand David that was played, but also other pieces, like the trombone concerto by Eugene Reiche(1878-1946) written somewhat like the concerto by David. PROMINENT TROMBONE PLAYERS OF THE 20 .
IndividualswithsurnameRABBACH

Individuals with surname RABBACH
[Q]: [CPH:DOXhas5competitionshereisanoverviewofsomethebestfilmsyoucanwatchatthisyear'sfestival.]
[A]: [CPH:DOX has 5 competitions here is an overview of some the best films you can watch at this year's festival.]
Problem: Add spaces: Snowmenareusuallyconstructedbychildren;however,adultssometimesalsoparticipate.

Spaces added: Snowmen are usually constructed by children; however, adults sometimes also participate.
This text is missing some spaces, please add them: Thisappliesnotjusttocomparativelyminorornamentalelementsorframes,butencompassesthewholeofthehousingsurface.
This applies not just to comparatively minor ornamental elements or frames, but encompasses the whole of the housing surface.
[Q]: [TheDynamicsofExistence::Read"TheIndividualandHisDynamics."]
[A]:
[The Dynamics of Existence :: Read "The Individual and His Dynamics."]