Question d'entraînement gratuite

TOEFL iBT 2026 Listen to an Academic Talk : une vraie question d'entraînement

Voici une série de questions tirée de nos sujets blancs, exactement telle qu'elle apparaît à l'examen. L'examen lui-même est en anglais.

1. What is the main topic of the talk?

How erosion gradually flattens all ancient mountain belts over timeWhy the crust beneath the Scandinavian Caledonides is thicker than averageHow icebergs can be used to predict the height of mountain rangesWhy some old mountain ranges remain elevated despite millions of years of erosion

2. According to the professor, what did the measurements beneath the Scandinavian Caledonides reveal?

The crust there is unusually thick and light compared with other ancient beltsThe mountain range is supported by a hot, buoyant region in the upper mantleErosion has removed the mantle root that once held the mountains upThe dense crust above the mantle root has been pushed downward by the cork effect

3. Why does the professor mention a cork held underwater?

To show how mantle heat melts the base of the crustTo explain why erosion can cause a mountain range to riseTo compare the density of crustal rock with that of seawaterTo argue that the iceberg model should be abandoned entirely

4. What can be inferred about the professor's view of the traditional iceberg model?

It remains the best explanation for the Scandinavian CaledonidesIt correctly describes how erosion wears down mountain beltsIt is incomplete because it ignores support from the mantleIt applies only to mountain ranges that have already been flattened

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