Line 28 (“Spring . . . wonder”) most clearly marks a shift in the speaker’s focus from the practical task at hand to

In line 28 we can see a shift in the speaker's focus to speculation about the limits that nature has.

Explanation:

In line 28, the speaker's approach changes and he begins to address nature in a more influential and profound way, showing the limits of it. This is to show that even something great like nature, has fineness, that is, it has limitations. This can be applied to the physical sense of nature, or even to the subjective and more conceptual sense of the effect of nature.

hello and welcome to the town of river dale. if you come to river-dale trust me you wouldn't want to leave.  

where are the following words.. you cant just ask a question and expect people to know the choices.