Final answer:
The line that best expresses the speaker's uncertainty about the owner is: 'Whose woods these are I think I know. His house is in the village though.'
Step-by-step explanation:
The line that best expresses the speaker's uncertainty about the owner is: 'Whose woods these are I think I know. His house is in the village though.' In this line from the poem 'Stopping by Woods on a Snowy Evening' by Robert Frost, the speaker shows uncertainty about the ownership of the woods by using the word 'think' and contrasting it with the fact that the owner's house is in the village.