all medical practitioners including the army and the police forces ate frontliners in this pandimic thus they laed in fighting againts the cuvid 19 disease

recommended becuase why did he read the book? becuase it was recommended

demonstrative would be the answer.

remember, the goal of an adjective clause is to add more information to a noun or a pronoun. as you can see from the examples above, you can add information by including a longer adjective clause or tighten up a sentence by turning the adjective clause into an adjective phrase.