has been enveloping
-ha estado envolviendo
Presente perfecto progresivo para el sujeto he/she del verbo envelop.

envelop

The book, while being purely divulgative and easy to read, states the reasons which led those responsible for such programs to choose the aura of secrecy which has been enveloping them for decades.
El libro, puramente divulgativo y de lectura ágil, pone de manifiesto los motivos que llevaron a los responsables de tales programas a optar por la aureola de secretismo que los ha rodeado durante décadas.
Palabra del día
anual