In Noun phrases^x, Underline^x

Hello, Question: Underline the phrase in these sentences (there may be more than one in a sentence) and write whether theu are noun phrase, verb phrase, adjective phrase, adverbial phrase or prepositional phrase. 1. I was too timid (adjective phrase) to approach any of the white people....

Yes, it is possible for a noun phrase to have two heads, or more. If "NHS" mrefers to both the clinics and the centres (not just to the clinics) then the head is, as you said, "clinics and centres". I don't know in which way you are asked to go about syntactic analysis. What I would do,...