Answer:
ABBA
Step-by-step explanation:
In a poem generally the last word of each line indicates the rhyming scheme. It is denoted be letters ABC etc. The first word of the first line is taken as A in a stanza and the last word of each line is compared with it. If the last word of the second line rhymes with the word in the first line then we write the rhyme scheme as AABB. Where B is the another word rhyming with the last word of the fourth line and so on.
Here sky (A) rhymes with lie (A) and air (B) rhymes with fair (B).
So, the rhyming scheme of this stanza is ABBA.