37. The word "aided" in line 12 is closest in meaning to
(A) reversed
(B) helped
(C) reformed
(D) counted

33. The word "agents" in line 5 is closest in meaning to (A) dangers (B) examples (C) areas (D) causes

34. Why are marine organisms good candidates for fossilization? (A) they have more fleshy structures than land organisms. (B) It is likely that they will be buried rapidly (C) The water environment speeds the decay caused by bacteria. (D) It takes longer for them to be preserved.

35. The fact that the "land is largely the site of erosion" (line 7) is significant because (A) erosion is less destructive than sedimentation (B) fossils are most common in areas subject to erosion (C) erosion contributes to the destruction of skeletal remains (D) few organisms live in areas that experience extensive erosion

36. According to the passage, why were the remains of organisms trapped in swamps better preserved for the fossil record than those that were not? (A) The swamp environment reduced the amount of bacterial decay. (B) Swamp waters contained higher amounts of materials such as calcium carbonate. (C) There were fewer sediments in swamps than in other bodies of water. (D) Swamp vegetation accelerated the decomposition of organisms.

38. It can be inferred that flood plains, deltas, and stream channels (lines 13-14) are similar in which of the following ways? (A) Animals rather than plants have been preserved at such locations. (B) Such locations are likely to be rich sources of fossils. (C) Fossilized human remains are only rarely found in such locations. (D) Rapid sedimentation in such locations makes it difficult to locate fossils.

39. What is the author's main point in paragraph 3? (A) Weathering makes it impossible to identify many fossils. (B) Many fossils have been buried forever under the soil. (C) Fossils provide a limited sample of ancient organisms. (D) It is easier to find the remains of plants than animals.

40. Why does the author mention "aragonite" in line 26 (A) To explain why fossils are rare (B) To compare aragonite fossils and calcite fossils (C) To argue that certain fossils are more informative than others (D) To illustrate the kinds of inorganic hard parts that can form fossils

41. What does the passage mainly discuss? (A) The ecology of oak trees (B) Factors that determine the feeding habits of Squirrels (C) Various species of animals that promote the dispersal of tree seeds (D) The relationship between squirrels and oak trees

42. The word "they" in line 7 refers to (A) oak forests (B) acorns (C) squirrels (D) predators

43. According to the passage, what do squirrels do when large quantities of acorns are available? (A) They do not store acorns. (B) They eat more than 74 percent of available acorns. (C) They do not retrieve all the acorns that they have stored. (D) They hide acorns in tree cavities.