A words in context question with a concluding blank tests whether you can work out a word's meaning from a described process. Read the sentence with the blank, then follow the process it sums up. A signal such as therefore makes the blank name a result, so predict that result in plain words. If the sentence gives two effects, test both against each word's meaning. A word that fits only one effect isn't precise enough.
Hints
- Hint 1
Start with the final sentence’s two effects. What must the missing verb describe about the inherited course?
- Hint 2
Read the middle sentence for the link between downward cutting and sideways movement. Use both details to predict what happened to the old course.
Step-by-step
Follow the cause and effect
Step 1Read the blank as a result
The geologists find that the channel predates the uplift, so the river’s route was already there when the rock began rising. What does the final sentence ask us to name? This interaction therefore signals a result, so the blank describes what the river and rising rock did to that existing route.
- Step 2
Predict how the course changed
How did the course change if the river cut downward fast enough to maintain its route? It stayed on the same path while carving deeper into the rising rock, so preserving the route didn’t mean leaving the channel unchanged. The cutting produced steep walls that increasingly restricted lateral migration, which means the river had less room to shift sideways. Let’s predict made the old course more firmly fixed in place, because the deeper channel increasingly held the river to its existing path.
- Step 3
Reject changes the text doesn’t show
Diverted means sent in a different direction, which doesn’t fit preserving its position. Prolonged means made to last longer, but the text describes greater depth and less room to shift, not extra time. Reinstated means restored after being removed, and nothing here shows the old course disappearing and then returning.
- Step 4
Match both effects
Entrenched means fixed firmly in place and hard to move. Does it cover both preserving its position and deepening its expression in the landscape? The word’s sense of being dug in fits both: the channel becomes deeper, and that depth holds the existing route more firmly. Choice C.