Key to test 1  

1. (B) To "prevail" means "to exist" or "to occur more prominently or notably."

2. (D) The phrase "the three most prominent factors" indicates there are "other factors" that may not be as prominent.

3. (C) The phrase "these eccentricities" refers to the movements of the Earth. "The pattern of insolation... " is not a movement of the Earth.

4. (B) The phrase "the match between periods of peak insolation and most intense glaciation were not exact" means that the periods did not occur at the same time. The peaks did not match.

5. (A) The author is using the flat plane image "to help the reader visualize" how the Earth moves in and out of a plane.

6. (D) The Earth, "our planet," is plunged into cold periods periodically.

7. (D) Space debris reduces "the amount of solar energy reaching the Earth." This causes regular cold periods.

8. (A) Muller and MacDonald's theory is supported by the fossil record, whereas Milankovitch's theory is not ("The climate records...  not matching his predicted cycles").

9. (A) When someone is "persuaded" or "convinced," they have been shown evidence that makes them believe something.

10. (C) The problem with Muller and MacDonald's theory is that "the amount of dust" that reaches Earth in comparison to the debris from volcanoes appears too small to cool temperatures sufficiently.

11. The 4th square. The phrase "Earth is at its furthest from the sun" indicates that this is a detail related to the Earth's orbit around the sun. This would follow the sentence that discusses the elliptical nature of the Earth's orbit.

12.

Flaws in the Milankovitch Cycles Theory

(A) "Data of climate records... " - Milankovitch's predicted intervals of sunlight do not coincide with the climate records.
(B) "Temperature rises... " - The Nevada lake temperature increased before Milankovitch's predicted peaks of sunlight.

(D) "The inconsistency... " - Milankovitch's predicted cycles do not always match the periods of most glaciation.

(H) "The lack of clear support... " - The data from the ocean sediments does not coincide with Milankovitch's predicted years of glaciation

Flaws in the Muller and McDonald Theory

(E) "The relatively mild effect... " - The mild effect of volcanic eruptions on the climate does not support Muller and MacDonald's theory that interstellar debris affects the amount of sunlight that reaches the Earth.

(G) "The relatively small amount... " - There is not enough interstellar debris reaching Earth to support Muller and MacDonald's theory that this dust blocks sunlight.

(I) "The lack of physical evidence... " - Even though the glaciation corresponds to the periods of the Earth's moving through debris, Muller and MacDonald's theory is not supported by much physical evidence of changes in energy levels.