Final answer:
The sentence 'You can walk on the bridge ________ you can walk on the grass' requires a conditional conjunction like 'if' or an alternative conjunction like 'or', depending on the context. Literary examples illustrate various contexts in which movement related to bridges and grass is depicted in literature.
Step-by-step explanation:
The sentence provided by the student is a conditional sentence and requires a conjunction to link two clauses. In English, conditional sentences often use conjunctions like 'if', 'unless', or 'provided that' to show the condition under which something will happen. The gap in the sentence 'You can walk on the bridge ________ you can walk on the grass.' could be filled with different conjunctions depending on the intended meaning.
For instance, if the intention is to express that one action is allowed only if another action is allowed, the word 'if' might be used: 'You can walk on the bridge if you can walk on the grass.' However, if the intention is that walking on the bridge is an alternative to walking on the grass, 'or' could be used: 'You can walk on the bridge or you can walk on the grass.'
The excerpts provided from the literature beautifully illustrate various forms of movement and pathways, be it over grass, bridges, or roads. They highlight the different contexts in which these settings appear in literacy works, from a metaphor for choice and direction in Robert Frost's poetry to the depiction of movement and setting in Zane Grey's 'Riders of the Purple Sage'.