( ( ( Have ( ( the vents ) ( to ( the ( heating ( or ( air-conditioning system ) ) ) ) ) ) ) ( vacuumed ( by ( a ( professional service ) ) ) ) ) . )
(ROOT (SQ (VBP Have) (NP (NP (DT the) (NNS vents)) (PP (TO to) (NP (DT the) (NN heating) (CC or) (NN air-conditioning) (NN system)))) (VP (VBN vacuumed) (PP (IN by) (NP (DT a) (JJ professional) (NN service)))) (. .)))
Have the vents to the heating or air-conditioning system vacuumed by a professional service.
(ROOT (S (NP (DT A) (JJ sealed) (, ,) (JJ vacuum-insulated) (NN reaction) (NN flask)) (VP (VBZ approximates) (NP (NP (DT the) (NN condition)) (PP (IN of) (NP (NP (DT a) (VBN isolated) (NN system)) (, ,) (SBAR (WHPP (IN in) (WHNP (WDT which))) (S (NP (CC neither) (NP (NN matter)) (CC nor) (NP (NN heat))) (VP (MD can) (VP (VB be) (VP (VBN exchanged) (PP (IN between) (NP (NN system) (CC and) (NNS surroundings)))))))))))) (. .)))
A sealed, vacuum-insulated reaction flask approximates the condition of a isolated system, in which neither matter nor heat can be exchanged between system and surroundings.