Question

complete the sentence with the correct correlative conjunctions. the peace lily is ____ a pretty houseplant ____ an excellent indoor air cleaner. not only... but also whether... or

Explanation:

"Not only... but also" is used to present two positive aspects (being a pretty houseplant and an excellent indoor air cleaner) of the peace lily. "Whether... or" is used for presenting alternatives or choices, which is not the case here as both are positive attributes of the plant.

Answer:

not only... but also