Right Answers

Blank 3: This is the easiest one to tackle first. If we look towards the end of the sentence, after the semi-colon, we can see a contrast happening with this structure: "Even with A, B", so we can use Math Strategy to solve this one. The left-hand side of the comma suggests that we have more roads and bridges now (improvement), and the right-hand side is talking about the environment (woods and rivers). To contrast the idea of the improvement in infrastructure, Blank 3 should be something like "challenge" or "difficulty".

The best match for this would be impediment, since it conveys the idea that the environment is challenging, even with the improved infrastructure.

Blank 2: Now, we can work backward from Blank 3 to solve Blank 2, also with the Math Strategy. The semi-colon signifies a continuation of the ideas. Looking to the right, we have the idea of the environment being challenging, so a similar idea should be expressed on the left. Since Blank 2 describes the place (environment), it should also be something like "challenging".

The best match here would be an unpropitious signaling that the environment is an "unlucky"/"unforgiving" place to traverse.

Blank 1: Now, we can do the same thing again! We can apply Math Strategy one last time, using the comma between Blank 1 and Blank 2. On the right side, we have the idea of the place being "challenging" to pass through, so the left-hand side should also convey this idea. So, similarly, Blank 1 should be filled with a word like "challenging".

The best match here would be impenetrable, which perfectly conveys the idea of the forest being challenging to get through.

The Wrong Answers

Blank 1:

inconsiderable: This choice would be improper usage. It doesn't make sense to think of a forest as "inconsiderable".
uncultivated: This choice has no evidence. There's nothing in the passage regarding any kind of farming happening at the forest.

Blank 2:

a makeshift: This choice has no evidence. There's nothing suggesting that the forest was fabricated quickly.
an unremarkable: This choice has no evidence. We don't know how typical or unusual the forest is compared with other forests.

Blank 3:

resource: This choice has no evidence. There's nothing mentioned about how we can make use of the forest.
passage: This choice has no evidence. We don't know if the forest is an important route.