37. What did Harry Hammond Hess realize in the 1950s when his team continued exploring
the ocean floor and discovered the Mid-Atlantic Ridge?
A. He realized that the oceanic crust is older than the continental crust.
B. He realized that Alfred Wegener's Continental Drift Theory is not true.
C. He realized that the oceanic crusts near the Mid-Atlantic Ridge are thicker and less dense.
D. He realized that the Earth's crust had been moving away on each side of oceanic ridges,
down the Atlantic and Pacific Oceans.
38. What strong evidence discovered by our scientist that Earth's magnetic reversal had been
happening in the past?
A. The magnetic reversal occurrence is supported by magnetic patterns in magnetic rocks
found on the ocean floor.
B. The ages of the rocks on the ocean floor are constantly changing.
C. The magnetic field of the Earth becomes weaker.
D. The Earth's magnetic field is fluctuating.
39. If there are MORE mid-ocean ridges than subduction zones, what happens to the ocean?
A. It gets larger.
B. It gets smaller.
C. It sinks.
D. Nothing will change.
40. What do ancient glacier scars found in rock surfaces in Africa tells about its climate in the past?
A. The continents have not moved.
B. Africa has always been near the equator.
C. Africa was once in an area of the Earth that had a very cold climate.
D. Africa was once covered with ice sheets but did not move ever since.​