Which two consecutive lines from the poem contain a slant rhyme?

the wood pile
by robert frost
out walking in the frozen swamp one grey day
i paused and said, "i will turn back from here.
no, i will go on farther—and we shall see."
the hard snow held me, save where now and then
5 one foot went down. the view was all in lines
straight up and down of tall slim trees
too much alike to mark or name a place by
so as to say for certain i was here
or somewhere else: i was just far from home.
10 a small bird flew before me. he was careful
to put a tree between us when he lighted,
and say no word to tell me who he was
who was so foolish as to think what he thought.
he thought that i was after him for a feather—
15 the white one in his tail; like one who takes
everything said as personal to himself.
one flight out sideways would have undeceived him.
and then there was a pile of wood for which
i forgot him and let his little fear
20 carry him off the way i might have gone,
without so much as wishing him good-night.
he went behind it to make his last stand.
it was a cord of maple, cut and split
and piled—and measured, four by four by eight.
25 and not another like it could i see.
no runner tracks in this year's snow looped near it.
and it was older sure than this year's cutting,
or even last year's or the year's before.
the wood was grey and the bark warping off it
30 and the pile somewhat sunken. clematis
had wound strings round and round it like a bundle.
what held it though on one side was a tree
still growing, and on one a stake and prop,
these latter about to fall. i thought that only
35 someone who lived in turning to fresh tasks
could so forget his handiwork on which
he spent himself, the labor of his axe,
and leave it there far from a useful fireplace
to warm the frozen swamp as best it could
40 with the slow smokeless burning of decay.