beneficial
The definition for beneficial is "Helpful." Used in a sentence: there is no doubt that eating vegetables is beneficial to one's health.
derelict
The definition for derelict is "Abandoned." Used in a sentence: The derelict house was condemned as a public hazard.
dubious
The definition for dubious is "Questionable." Used in a sentence: Karl found Kevin's claim that he was sick dubious, as he had just seen him playing football.
exalt
The definition for exalt is "To elevate by praise." Used in a sentence: The fireman was publicly exalted for his heroism.
extol
The definition for extol is "To praise highly." Used in a sentence: The statesman extolled the ambassador who single–handedly negotiated the peace treaty.