(i) Sandburg thinks the fog is like a cat that comes silently so that no one can sense it arrival.

(ii)As per the poet, the fog comes very silently like a cat.

(iii)‘It’ refers to the fog.

(iv)The three things that tell us that the fog is like a cat are as follows:

(a) The fog comes on its little cat feet: This means that the fog enters silently just like cat.

(b) It sits looking over harbour and city: The fog is compared to cat as cats also like to sit and look here and there and fog is also looking while it sits over the city.

(c)On silent haunches and then moves on: The fog sits on her bended legs just like cat and then moves away very quickly and silently, just like a c